✅Answer: Please pay attention to the following narrations:

1 عن أبی عبدالله قال: وضع رسول اللَّه الزکاة علی تسعة أشیاء الْحِنْطَة و الشَّعِیر و التَّمْر و الزَّبِیب و الذَّهَب و الْفِضَّة و الْإِبِل و الْبَقَر و الْغَنَم و عَفَا عَمَّا سِوَی ذَلِک

📚 Al-Kafi, Vol. 3, p. 509

Imam Sadiq (peace be upon him) said: The Messenger of Allah (peace be upon him and his family) placed Zakat on nine things: wheat, barley, dates, raisins, gold, silver, camels, cows, and sheep, and he exempted what is other than these!

2 From Muhammad ibn Al-Tayyar, he said: I asked Abu Abdullah (peace be upon him) about what Zakat is obligatory on. He said: On nine things: gold, silver, wheat, barley, dates, raisins, camels, cows, and sheep, and the Messenger of Allah (peace be upon him) exempted what is other than that. I said: May Allah set your affairs right, indeed we have a lot of grain. He said: And what is it? I said: Rice. He said: Yes, how much there is of it. I said: Is there Zakat on it? So he rebuked me and said: I say to you that the Messenger of Allah (peace be upon him and his family) exempted what is other than that, and you say to me: We have a lot of grain, is there Zakat on it?

📚 Al-Tahdheeb, Vol. 4, p. 4

Muhammad ibn Tayyar said: I asked Imam Sadiq (peace be upon him) about what Zakat is obligatory on; the Imam said: On nine things: gold, silver, wheat, barley, dates, raisins, camels, cows, and sheep, and the Messenger of Allah (peace be upon him and his family) exempted what is other than these!

I said: May Allah set your affairs right, indeed we have a lot of grain! He said: What is it? I said: Rice! He said: Yes! How much there is! I said: Is there Zakat on it? So the Imam prevented me and said: I tell you that the Messenger of Allah (peace be upon him and his family) exempted what is other than these nine items, and you say: We have a lot of grain, is there Zakat on it?!

3 From Abu Ja'far, he said: There is no Zakat on anything that the earth produces, such as rice, corn, chickpeas, lentils, and all other grains and fruits, other than these four types, even if its value is high, unless it becomes money that is sold for gold or silver and you hoard that gold or silver until a year has passed on it while it is gold or silver, then you pay Zakat from every 200 dirhams five dirhams and from every twenty dinars half a dinar.

📚 Al-Tahdheeb, Vol. 4, p. 6

Imam Baqir (peace be upon him) said: There is no Zakat on anything that the earth produces, such as rice, corn, chickpeas, lentils, and all other grains and fruits, other than these four types, even if its value is high, unless it becomes money that is sold for gold and silver and you hoard that gold and silver until a year has passed on it while it is gold or silver, then Zakat is paid from every 200 dirhams 5 dirhams and from every twenty dinars, half a dinar!

4 From Abu Abdullah, he was asked about Zakat, so he said: The Messenger of Allah placed Zakat on nine things and exempted what is other than that: wheat, barley, dates, raisins, gold, silver, cows, sheep, and camels!

The questioner said: What about corn? The Imam became angry and said: By Allah, during the time of the Messenger of Allah (peace be upon him and his family), there were sesame seeds, corn, millet, and all of that!

He said: They say that those were not present during the time of the Messenger of Allah (peace be upon him and his family) and that the Prophet placed Zakat on nine things because nothing else was present before him!

The Imam said: They lie! Is exemption except from something that has existed?! By Allah, I do not know of anything on which Zakat is due other than these (nine items), so let whoever wishes believe and let whoever wishes disbelieve!

✅ Based on the above narrations and others, the Messenger of Allah (peace be upon him and his family) placed Zakat on nine things, which are: wheat, barley, dates, raisins, gold, silver, cows, sheep, and camels, each of which has a specific nisaab (taxable amount) and rulings, and he exempted other grains and fruits and did not place Zakat on them, and this matter has been mentioned in several narrations.

However, there are also narrations that have considered other grains as items of Zakat, and they are in conflict with the first group of narrations, but these narrations are not applicable due to their agreement with the public, since most of the public believe in the existence of Zakat on all grains that reach the nisaab of 300 sa' and the evidence for this is clear in narrations such as narration 4 and others.