✅ Answer: Pay attention to the following narrations:

1⃣عَنِ الْفَضْلِ بْنِ شَاذَانَ عَنِ الرِّضَا فِي كِتَابِهِ إِلَى الْمَأْمُونِ قَالَ: زَكَاةُ الْفِطْرِ فَرِيضَةٌ عَلَى كُلِّ رَأْسٍ صَغِيرٍ أَوْ كَبِيرٍ حُرٍّ أَوْ عَبْدٍ ذَكَرٍ أَوْ أُنْثَى مِنَ الْحِنْطَةِ وَ الشَّعِيرِ وَ التَّمْرِ وَ الزَّبِيبِ صَاعٌ وَ هُوَ أَرْبَعَةُ أَمْدَادٍ.

📚 Uyun Akhbar al-Rida, peace be upon him, Vol. 2, p. 123

Imam Reza, peace be upon him, wrote in his letter to Ma’mun: Zakat al-Fitra for every individual—whether young or old, free or slave, male or female—is obligatory, amounting to one sa’ (which is four mudds) of wheat, barley, dates, or raisins!

2⃣ عَنْ مُحَمَّدِ بْنِ أَحْمَدَ بْنِ يَحْيَى عَنْ جَعْفَرِ بْنِ إِبْرَاهِيمَ بْنِ مُحَمَّدٍ الْهَمَذَانِيِّ وَ كَانَ مَعَنَا حَاجّاً قَالَ: کَتَبْتُ إِلَی أَبِی الْحَسَنِ عَلَی یَدَیْ أَبِی جُعِلْتُ فِدَاکَ إِنَّ أَصْحَابَنَا اخْتَلَفُوا فِی الصَّاعِ بَعْضُهُمْ یَقُولُ الْفِطْرَةُ بِصَاعِ الْمَدَنِیِّ وَ بَعْضُهُمْ یَقُولُ بِصَاعِ الْعِرَاقِیِّ فَکَتَبَ إِلَیَّ الصَّاعُ سِتَّةُ أَرْطَالٍ بِالْمَدَنِیِّ وَ تِسْعَةُ أَرْطَالٍ بِالْعِرَاقِیِّ قَالَ وَ أَخْبَرَنِی أَنَّهُ یَکُونُ بِالْوَزْنِ أَلْفاً وَ مِائَةً وَ سَبْعِینَ وَزْنَةً[دِرْهَماً]

📚 Al-Kafi, Vol. 4, p. 172

Ja’far ibn Ibrahim ibn Muhammad al-Hamadhani says: I wrote a letter to Abu al-Hasan, peace be upon him, through my father, saying: May I be your ransom! Our companions have differed regarding the sa’. Some say Zakat al-Fitra is based on the Madinan sa’, while others say it is based on the Iraqi sa’!

The Imam replied to me: Every sa’ is 6 Madinan ratls or 9 Iraqi ratls!

He says: And he informed me that every sa’ by weight (in dirhams) is 1,170 dirhams!

3⃣ عَنْ إِبْرَاهِيمَ بْنِ مُحَمَّدٍ الْهَمَذَانِيِّ أَنَّ أَبَا الْحَسَنِ صَاحِبَ الْعَسْكَرِ كَتَبَ إِلَيْهِ فِي حَدِيثٍ الْفِطْرَةُ عَلَيْكَ وَ عَلَى النَّاسِ كُلِّهِمْ وَ مَنْ تَعُولُ ذَكَراً كَانَ أَوْ أُنْثَى صَغِيراً أَوْ كَبِيراً حُرّاً أَوْ عَبْداً فَطِيماً أَوْ رَضِيعاً تَدْفَعُهُ وَزْناً سِتَّةَ أَرْطَالٍ بِرِطْلِ الْمَدِينَةِ- وَ الرِّطْلُ مِائَةٌ وَ خَمْسَةٌ وَ تِسْعُونَ دِرْهَماً يَكُونُ الْفِطْرَةُ أَلْفاً وَ مِائَةً وَ سَبْعِينَ دِرْهَماً.

📚 Al-Tahdhib, Vol. 4, p. 79

Ibrahim ibn Muhammad al-Hamadhani narrated that Abu al-Hasan al-Askari (Imam Ali al-Naqi), peace be upon him, wrote to him: Zakat al-Fitra is obligatory upon you and all people, and those whose sustenance you provide—whether male or female, young or old, free or slave, breastfeeding or weaned—amounting to 6 Madinan ratls by weight. Each ratl is 195 dirhams, making Zakat al-Fitra 1,170 dirhams!

4⃣عَنْ سُلَيْمَانَ بْنِ حَفْصٍ الْمَرْوَزِيِّ قَالَ: قَالَ أَبُو الْحَسَنِ مُوسَى بْنُ جَعْفَرٍ الْغُسْلُ بِصَاعٍ مِنْ مَاءٍ وَ الْوُضُوءُ بِمُدٍّ مِنْ مَاءٍ وَ صَاعُ النَّبِيِّ خَمْسَةُ أَمْدَادٍ وَ الْمُدُّ وَزْنُ مِائَتَيْنِ وَ ثَمَانِينَ دِرْهَماً وَ الدِّرْهَمُ وَزْنُ سِتَّةِ دَوَانِيقَ وَ الدَّانِقُ وَزْنُ سِتِّ حَبَّاتٍ وَ الْحَبَّةُ وَزْنُ حَبَّتَيْ شَعِيرٍ مِنْ أَوْسَطِ الْحَبِّ لَا مِنْ صِغَارِهِ وَ لَا مِنْ كِبَارِهِ.

📚 Al-Tahdhib, Vol. 1, p. 135

📚 Al-Faqih, Vol. 1, p. 34 (with slight differences)

Imam Kazim, peace be upon him, said: Ghusl is performed with one sa’ of water, and wudu with one mudd of water. The Prophet’s sa’, peace and blessings be upon him and his family, is 5 mudds, and a mudd weighs 280 dirhams. A dirham weighs 6 daniqs, a daniq weighs 6 grains, and a grain weighs two medium barley grains—not the small ones nor the large ones!

✅ The sa’ was a measuring container during the time of the Messenger of Allah, peace and blessings be upon him and his family, upon which some legal weights, including Zakat al-Fitra, were based.

Since it was merely a container, in different times and regions, it was calculated according to their local weight units to determine its amount.

To calculate the sa’ in grams, which is relevant to our time, various methods have been employed, and differences have emerged.

However, two prominent and general methods are as follows:

1⃣ Calculation based on the well-known opinions of specific and general jurists, lexicographers, and some narrations

2⃣ Calculation based on existing narrations

✅ In the first method of calculating the sa’, it is argued that the weight of a dirham, one of the bases for calculating the sa’, mudd, etc., varied over time, but the weight of a legal dinar, equivalent to a legal mithqal, remained constant. Using the well-known (non-narrational) assertion that 10 dirhams equal 7 dinars or legal mithqals, and combining it with narrations 2⃣ and 3⃣—where the sa’ is specified as 1,170 dirhams—they conclude that each sa’ equals 819 legal mithqals or its equivalent in the jeweler’s mithqal. Based on the well-known (non-narrational) weight of a legal mithqal, they calculate the sa’ and subsequently the mudd.

With this standard, although a legal mithqal has been said to weigh 4.265 grams, using another well-known weight of 3.456 grams, the weight of a sa’ is calculated as approximately 2,831 grams, with some minor variations. Alternatively, based on the well-known jeweler’s mithqal, it is calculated as about one Tabriz man or 3 kilograms. Consequently, each mudd, established in Shia narrations as one-fourth of a sa’, is calculated as 750 grams.

✅ As observed, this calculation relies less on narrations and more on well-known quantities.

✅ However, if we aim to maximize the use of existing narrations and base the sa’, mudd, and subsequent weights like daniq and dirham on Shia narrations, we must first outline the standards from the narrations mentioned.

The following points are clear from the above narrations:

1⃣ Although one or two narrations state that each sa’ equals 5 mudds, based on over 30 authentic Shia narrations, such as narration 1⃣, each sa’ equals 4 mudds.

2⃣ According to narrations 2⃣ and 3⃣, which are well-known among Shia, each sa’ weighs 1,170 dirhams. The figure of 1,400 dirhams for a sa’ in narration 4⃣ is rare and not acted upon by Shia.

3⃣ According to the above narrations, each sa’ equals 9 Iraqi ratls and 6 Madinan ratls, meaning each mudd is 2.25 Iraqi ratls and 1.5 Madinan ratls.

4⃣ The fourth narration, by Sulayman ibn Hafs Marwazi, contains various parts, some of which conflict with other narrations and are not actionable due to their rarity. However, it is the only place in Shia jurisprudence where the calculation of a dirham—a key measure for calculating sa’, mudd, ratl, daniq, and the amount of kurr water—is detailed. Since the dirham calculation in this narration has no conflicting narration, we derive the dirham’s weight from it and use it with other narrations to calculate the remaining weights.

5⃣ In the narration of Sulayman ibn Hafs Marwazi, each dirham equals 6 daniqs, each daniq equals 6 grains, and each grain equals 2 medium barley grains. Thus, each dirham equals 72 medium barley grains.

The only issue in this calculation is that barley grains vary slightly across times and regions, but an approximate weight for a medium barley grain can be determined, especially with modern tools, to serve as a standard for calculating these weights.

To this end:

✅ We multiply the weight of one medium barley grain by 2 to obtain the weight of a grain.

✅ We multiply the weight of a grain by 6 to obtain the weight of a daniq.

✅ We multiply the weight of a daniq by 6 to obtain the weight of a dirham.

✅ We multiply the weight of a dirham by 1,170, as per narrations 2⃣ and 3⃣, to obtain the weight of a sa’.

✅ We divide the weight of a sa’ by 4 to obtain the weight of a mudd.

✅ We divide the weight of the resulting sa’ by 9 to obtain the weight of an Iraqi ratl.

✅ We divide the weight of the resulting sa’ by 6 to obtain the weight of a Madinan ratl.

And so on...

✅ With the above explanation, believers can determine these amounts in grams by obtaining the precise weight of a medium barley grain.

✅ The author of these lines, by weighing various barley grains in large quantities and averaging them, arrived at a weight of 0.041 grams for each medium barley grain. Based on this and the above narrations, the following weights were calculated:

0.041 * 2 = 0.082 grams (weight of a grain)

0.082 * 6 = 0.492 grams (weight of a daniq)

0.492 * 6 = 2.952 grams (weight of a dirham)

2.952 * 1170 = 3453.84 grams (weight of a sa’)

3453.84 ÷ 9 = 383.76 grams (one Iraqi ratl)

3453.84 ÷ 6 = 575.64 grams (one Madinan ratl)

✅ 👈 According to this calculation, each sa’ is approximately 3.5 kilograms, and each mudd is approximately 875 grams.

According to the first calculation, each sa’ ranges from approximately 2,830.464 to 3,000 grams, and each mudd from approximately 707.616 to 750 grams, though it has become customary to consider a sa’ as 3 kilograms and a mudd as 750 grams.

👈 According to the second narrational calculation,

👈 Each sa’ is approximately 3.5 kilograms,

and each mudd is approximately 875 grams, though it is sometimes calculated slightly higher.

To act with caution, in cases like Zakat al-Fitra, the second calculation is considered, while in cases like determining the minimum amount (nisab) of wheat and barley for zakat, the first calculation is used.

✅ Allama Majlisi, in his book 'Awzan al-Maqadir,' after calculating the weight of a sa’ and mudd using various standards in terms of mithqals and Shahi man, notes that due to the differences in these amounts across various standards, it is better to exercise caution. He suggests calculating things like fidya, fitra, and kaffara based on the higher amount and things like the nisab of zakat for wheat, barley, etc., based on the lower amount, which is an appropriate application of caution given the nature of this issue.

2⃣ The weight of a dirham, calculated as 2.952 grams based on weighing medium barley grains, is approximately equivalent to the silver dirhams remaining from the time of the Ahl al-Bayt, peace be upon them, which researchers have weighed!

3⃣ If, in the first calculation method, we consider the weight of 4.265 grams—mentioned alongside 3.456 grams for a legal mithqal and dinar—the weight of a sa’ becomes nearly equal to the second calculation method:

4.265 * 819 = 3,493.035 grams

Meaning, with a mithqal of 4.265 grams,

👈 Each sa’ is approximately 3.5 kilograms,

and each mudd is approximately 875 grams.

🔷 Relying solely on the narration of Sulayman ibn Hafs Marwazi (the fourth narration), with a standard of 0.041 grams per barley grain, without considering other narrations, results in a mudd of approximately 826 grams and a sa’ of about 4,132 grams. However, due to the rarity and conflict of some parts of this narration with others, it is not entirely reliable. The rare and conflicting parts of this narration are supplemented and corrected with other narrations.

✅ Various other discussions could be raised on this matter, but to resolve all ambiguities surrounding this issue, we repeatedly and earnestly say:

اللَّهُمَّ صَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ

وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ