✅ Answer: Please pay attention to the following narrations:

Doubts in prayer

Doubt between rak'ahs

1 عَنْ أَبِي عَبْدِ اللَّهِ أَنَّهُ قَالَ لَهُ يَا عَمَّارُ أَجْمَعُ لَكَ السَّهْوَ كُلَّهُ فِي كَلِمَتَيْنِ مَتَى مَا شَكَكْتَ فَخُذْ بِالْأَكْثَرِ فَإِذَا سَلَّمْتَ فَأَتِمَّ مَا ظَنَنْتَ أَنَّكَ نَقَصْتَ

📚 Al-Faqih Vol. 1, p. 340

Imam Sadiq (peace be upon him) said: O 'Ammar! I will summarize all the rulings of forgetfulness for you in two words! Whenever you doubt, build upon the greater number, and when you have performed the salam, complete what you think you have missed (with the prayer known as 'Salat al-Ihtiyat')!

2 عَنْ أَبِي عَبْدِ اللَّهِ قَالَ: إِذَا لَمْ تَدْرِ ثَلَاثاً صَلَّيْتَ أَوْ أَرْبَعاً وَ وَقَعَ رَأْيُكَ عَلَى الثَّلَاثِ فَابْنِ عَلَى الثَّلَاثِ وَ إِنْ وَقَعَ رَأْيُكَ عَلَى الْأَرْبَعِ فَسَلِّمْ وَ انْصَرِفْ وَ إِنِ اعْتَدَلَ وَهْمُكَ فَانْصَرِفْ وَ صَلِّ رَكْعَتَيْنِ وَ أَنْتَ جَالِسٌ.

📚 Al-Kafi Vol. 3, p. 353

Imam Sadiq (peace be upon him) said: When you do not know whether you have prayed three rak'ahs or four, and your thought is on three rak'ahs, then build upon three rak'ahs, and if your thought is on four rak'ahs, then perform the salam and turn away from the prayer, and if your thought is equal (between the two), complete the prayer and pray two rak'ahs while sitting!

3 زُرَارَةَ عَن أَحَدِهِمَا قَالَ: قُلْتُ لَهُ رَجُلٌ لَمْ يَدْرِ اثْنَتَيْنِ صَلَّى أَمْ ثَلَاثاً فَقَالَ إِنْ دَخَلَهُ الشَّكُّ بَعْدَ دُخُولِهِ فِي الثَّالِثَةِ مَضَى فِي الثَّالِثَةِ ثُمَّ صَلَّى الْأُخْرَى وَ لَا شَيْ ءَ عَلَيْهِ وَ يُسَلِّم

📚 Al-Kafi Vol. 3, p. 350

Zurarah said: I said to the Imam (peace be upon him): A person does not know whether he has prayed two rak'ahs or three! He said: If he doubts after entering the third rak'ah, he should build upon three rak'ahs (and complete the prayer) and then (after the prayer) pray one more rak'ah and there is nothing on him and he performs the salam.

4 ابْنِ أَبِي يَعْفُورٍ قال: سَأَلْتُ أَبَا عَبْدِ اللَّه عَنِ الرَّجُلِ لَا يَدْرِي رَكْعَتَيْنِ صَلَّى أَمْ أَرْبَعاً قَالَ يَتَشَهَّدُ وَ يُسَلِّمُ ثُمَّ يَقُومُ فَيُصَلِّي رَكْعَتَيْنِ و أَرْبَعَ سَجَدَاتٍ يَقْرَأُ فِيهِمَا بِفَاتِحَةِ الْكِتَابِ ثُمَّ يَتَشَهَّدُ وَ يُسَلِّمُ

📚 Al-Kafi Vol. 3, p. 352

Ibn Abi Ya'fur said: I asked Imam Sadiq (peace be upon him) about a person who does not know whether he has prayed two rak'ahs or four; he said: He performs the tashahhud and the salam, and then he stands up and prays two rak'ahs with four prostrations with only Surah Al-Hamd and then he performs the tashahhud and the salam.

5 عَنْ أَبِي عَبْدِ اللَّه قَالَ: فِيمَنْ لَا يَدْرِي أَ ثَلَاثاً صَلَّى أَمْ أَرْبَعاً وَ وَهْمُهُ فِي ذَلِكَ سَوَاءٌ قَالَ فَقَالَ إِذَا اعْتَدَلَ الْوَهْمُ فِي الثَّلَاثِ وَ الْأَرْبَعِ فَهُوَ بِالْخِيَارِ إِنْ شَاءَ صَلَّى رَكْعَةً وَ هُوَ قَائِمٌ وَ إِنْ شَاءَ صَلَّى رَكْعَتَيْنِ وَ أَرْبَعَ سَجَدَاتٍ (وَ هُوَ جَالِسٌ)

📚 Al-Kafi Vol. 3, p. 353

Imam Sadiq (peace be upon him) said about a person who does not know whether he has prayed three rak'ahs or four and his thought is equal in it: When the thought is equal, he is given the choice that if he wishes, he can pray one rak'ah standing, and if he wishes, he can pray two rak'ahs sitting with four prostrations.

6 عَنْ أَبِي عَبْدِ اللَّهِ قَالَ: إِنِ اسْتَوَى وَهْمُهُ فِي الثَّلَاثِ وَ الْأَرْبَعِ سَلَّمَ وَ صَلَّى رَكْعَتَيْنِ وَ أَرْبَعَ سَجَدَاتٍ بِفَاتِحَةِ الْكِتَابِ وَ هُوَ جَالِسٌ يُقَصِّرُ فِي التَّشَهُّدِ.

📚 Tahdhib Vol. 2, p. 185

Imam Sadiq (peace be upon him) said: If his thought is equal in three and four, he performs the salam and prays two rak'ahs sitting with four prostrations with Surah Al-Hamd and recites the tashahhud briefly.

7 عَنِ الْحَلَبِيِّ عَنْ أَبِي عَبْدِ اللَّه أَنَّهُ قَالَ: إِذَا لَمْ تَدْرِ اثْنَتَيْنِ صَلَّيْتَ أَمْ أَرْبَعاً وَ لَمْ يَذْهَبْ وَهْمُكَ إِلَى شَيْ ءٍ فَتَشَهَّدْ وَ سَلِّمْ ثُمَّ صَلِّ رَكْعَتَيْنِ وَ أَرْبَعَ سَجَدَاتٍ تَقْرَأُ فِيهِمَا بِأُمِّ الْكِتَابِ ثُمَّ تَشَهَّدُ وَ تُسَلِّمُ فَإِنْ كُنْتَ إِنَّمَا صَلَّيْتَ رَكْعَتَيْنِ كَانَتَا هَاتَانِ تَمَامَ الْأَرْبَعِ وَ إِنْ كُنْتَ صَلَّيْتَ أَرْبَعاً كَانَتَا هَاتَانِ نَافِلَةً.

📚 Al-Faqih Vol. 1, p. 349

Imam Sadiq (peace be upon him) said: If you do not know whether you have prayed two rak'ahs or four and your thought does not lean towards either side, then perform the tashahhud and the salam, then pray two rak'ahs with four prostrations in which you recite Surah Al-Hamd, and then perform the tashahhud and the salam. So if you have prayed two rak'ahs, these two rak'ahs will complete it, and if you have prayed four rak'ahs, these two rak'ahs will be considered a supererogatory prayer.

Doubts in prayer

8 عَنْ زُرَارَةَ عَنْ أَحَدِهِمَا فِي حَدِيثٍ قَالَ: قُلْتُ لَهُ مَنْ لَمْ يَدْرِ فِي أَرْبَعٍ هُوَ أَمْ فِي ثِنْتَيْنِ وَ قَدْ أَحْرَزَ الثِّنْتَيْنِ قَالَ يَرْكَعُ رَكْعَتَيْنِ وَ أَرْبَعَ سَجَدَاتٍ وَ هُوَ قَائِمٌ بِفَاتِحَةِ الْكِتَابِ- وَ يَتَشَهَّدُ وَ لَا شَيْ ءَ عَلَيْهِ الْحَدِيثَ.

📚 Al-Kafi Vol. 3, p. 351

The Imam said about a person who does not know whether he is in the fourth or second rak'ah and two rak'ahs are certain for him: (He builds upon 4 and after the prayer) he prays two rak'ahs with four prostrations with Surah Al-Hamd and performs the tashahhud and there is nothing on him!

9 عَنْ أَبِي إِبْرَاهِيمَ قَالَ: قُلْتُ لِأَبِي عَبْدِ اللَّه رَجُلٌ لَا يَدْرِي اثْنَتَيْنِ صَلَّى أَمْ ثَلَاثاً أَمْ أَرْبَعاً فَقَالَ يُصَلِّي رَكْعَةً [رکعتین ] مِنْ قِيَامٍ ثُمَّ يُسَلِّمُ ثُمَّ يُصَلِّي رَكْعَتَيْنِ وَ هُوَ جَالِسٌ.

📚 Al-Faqih Vol. 1, p. 350

Abu Ibrahim said: A person does not know whether he has prayed two rak'ahs or three or four? He said: (According to hadith 1 , he builds upon 4 and after the prayer) he prays two rak'ahs standing, then performs the salam and then also prays two rak'ahs sitting.

10 عَنْ زَيْدٍ الشَّحَّامِ قَالَ: سَأَلْتُهُ عَنْ رَجُلٍ صَلَّى الْعَصْرَ سِتَّ رَكَعَاتٍ أَوْ خَمْسَ رَكَعَاتٍ قَالَ إِنِ اسْتَيْقَنَ أَنَّهُ صَلَّى خَمْساً أَوْ سِتّاً فَلْيُعِدْ وَ إِنْ كَانَ لَا يَدْرِي أَ زَادَ أَمْ نَقَصَ فَلْيُكَبِّرْ وَ هُوَ جَالِسٌ ثُمَّ لْيَرْكَعْ رَكْعَتَيْنِ يَقْرَأُ فِيهِمَا بِفَاتِحَةِ الْكِتَابِ فِي آخِرِ صَلَاتِهِ ثُمَّ يَتَشَهَّدُ الْحَدِيثَ.

📚 Al-Tahdhib Vol. 2, p. 352

Zayd al-Shahham said: I asked (Imam Sadiq, peace be upon him) about a person who has prayed the 'Asr prayer six rak'ahs or five rak'ahs; the Imam said: If he is certain that he has prayed five or six rak'ahs, he must repeat the prayer, and if he does not know whether he has missed or added, at the end of his prayer he says 'takbir' while sitting and prays two rak'ahs in which he recites only Surah Al-Hamd and then performs the tashahhud...

✅ Several points worth mentioning:

1 'Salat al-Ihtiyat' is one standing rak'ah or two standing or sitting rak'ahs, which are performed to compensate for some of the forgetfulness that occurs in the four-rak'ah prayers.

2 The Ahl al-Bayt (peace be upon them) did not give a specific name to this prayer, but it has become known as 'Salat al-Ihtiyat'.

3 As stated in its various narrations, in this prayer, only Al-Hamd is recited and it does not have a surah, and its ruku' and prostration do not differ from other prayers.

4 By the context of it being named a 'prayer' and the explicit mention in narration 🔟, saying the takbirat al-ihram at the beginning of this prayer is necessary.

5 In none of its narrations is there any mention of having a qunut for this prayer.

6 A brief (or moderate) tashahhud and performing the salam are explicitly mentioned in many of its narrations.

7 The audible and loud recitation of 'Bismillah al-Rahman al-Rahim' in this prayer is subject to the general rules regarding the audible recitation of 'Bismillah al-Rahman al-Rahim' and therefore it is recited audibly.

8 According to the general principle in hadith 1 , when forgetfulness is equal in four-rak'ah prayers, one should build on the greater number, and after completing that prayer, this prayer is performed in the ways mentioned and in the cases received in the narrations.

✅ In summary, the prayer known as 'Salat al-Ihtiyat,' which is performed in limited cases, is a prayer that is performed after completing the prayer, in which the takbirat al-ihram, ruku', sujud, tashahhud, and salam are performed, but its recitation is only Al-Hamd, and no qunut has been prescribed for it.

اللَّهُمَّ فَصَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ