The evidence for zakah on trade goods being obligatory
Question

What is the evidence for zakah on trade goods being obligatory? Because I have heard that there are some scholars who say that it is not obligatory to give zakah on them.
Praise be to Allah.The majority of scholars (including the four imams, Abu Haneefah, Maalik, ash-Shaafa‘i and Ahmad, may Allah have mercy on them) are of the view that it is obligatory to give zakah on trade goods.
They quoted a great deal of evidence for that from the Quran and Sunnah, and the words of the Sahaabah.
That evidence includes:
1.. The verse in which Allah, may He be exalted, says (interpretation of the): {O you who have believed, spend from the good things which you have earned and from that which We have produced for you from the earth} [al-Baqarah 2:267].
Mujaahid said: This was revealed concerning trade.
2.. It was narrated that Samurah ibn Jundub (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) would instruct us to give zakah on that which we prepared for sale. Narrated by Abu Dawood (1562). Classed as hasan by Ibn ‘Abd al-Barr; classed as da‘eef by al-Albaani in al-Irwa’ (827). Al-Haafiz said in at-Talkhees (2/391): There are some unknown narrators in its isnad. An-Nawawi said in al-Majmoo‘ (6/5): In its isnad there are a number of narrators whose status is not known.
3.. ad-Daaraqutni and al-Haakim narrated that Abu Dharr (may Allah be pleased with him) said: I heard the Messenger of Allah (blessings and peace of Allah be upon him) say: “On camels zakah is due; on sheep zakah is due; on cattle zakah is due; on garments zakah is due…” al-Haafiz said in at-Talkhees (2/391): There is nothing wrong with its isnad. End quote. It was classed as saheeh by an-Nawawi in al-Majmoo‘ (6/4).
This hadith was classed as saheeh by al-Haakim, although others had reservations about it.
This hadith indicates that obligatory to give zakah on trade goods, because no zakah is due on garments unless they are for trade, so the hadith should be understood as referring to that.
4.. al-Bukhaari (1468) and Muslim (983) narrated that Abu Hurayrah (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) sent ‘Umar to collect the zakah and it was said that Ibn Jameel, Khaalid ibn al-Waleed and al-‘Abbaas, the paternal uncle of the Messenger of Allah (blessings and peace of Allah be upon him), did not want to give it. The Messenger of Allah (blessings and peace of Allah be upon him) said: “The only reason for Ibn Jameel’s resentment is that he was poor then Allah made him rich! As for Khaalid, you are being unfair to Khaalid, for he is keeping his weapons and supplies (for jihad) in Allah’s cause. As for al-‘Abbaas, I will pay (his zakah), and as much again.”
An-Nawawi said in Sharh Muslim:
The linguists said that the word a‘taad (translated here as supplies) refers to tools of war, such as weapons, mounts and so on. What the hadith means is that they asked Khaalid to give zakah on his supplies, thinking that they were for trade, in which case zakah on them would be obligatory. But he said to them: I am not obliged to give you anything. So they told the Prophet (blessings and peace of Allah be upon him) that Khaalid was withholding zakah. But he said to them: You are being unfair to him, because he set them aside and allocated them for (jihad) in Allah’s cause before one year passed since he acquired them, so there is no zakah on them.
It may be that what is meant is that if zakah was due from him, he would have given it and would not have been stingy, because he allocated his wealth for Allah’s cause by way of donation, so how could he withhold that he was obliged to give? Some of the scholars understood from this that zakah must be given on trade goods. This is the view of the majority of scholars of the earlier and later generations, with the exception of Dawood. End quote.
5.. ash-Shaafa‘i, Ahmad, ‘Abd ar-Razzaaq and ad-Daaraqutni narrated from Abu ‘Amr ibn Himaas, from his father, that he said: I used to sell leather, and ‘Umar ibn al-Khattaab passed by me and said to me: Give zakah on your wealth. I said: O Ameer al-Mu’mineen, it is just leather. He said: Work out its value, then give zakah on it. Classed as da‘eef by al-Albaani in Irwa’ al-Ghaleel (828), because Abu ‘Amr ibn Himaas is unknown, but the other report supports it.
6.. it was narrated that ‘Abd ar-Rahmaan ibn ‘Abd al-Qaari said: I was in charge of the treasury (bayt al-maal) at the time of ‘Umar ibn al-Khattaab. When it was time to give people their stipends, he would collect the wealth of the merchants, then count it, both what was absent and what was present. Then he would take zakah from what was present for both what was present and what was absent. Classed as saheeh by Ibn Hazm in al-Muhalla (4/40).
7.. al-Bayhaqi narrated that Ibn ‘Umar (may Allah be pleased with him) said: There is no zakah on goods except those that are for trade. Classed as saheeh by Ibn Hazm in al-Muhalla (4/40) and by an-Nawawi in al-Majmoo‘ (6/5).
All this evidence, when taken together, proves that the ruling is sound. If each report is taken on its own, it may be subject to debate, but when all this evidence is put together, that gives it strength.
Hence the majority of scholars are of the view that it is obligatory to give zakah on trade goods, and the view that it is not obligatory is regarded as odd.
In fact, Ibn al-Mundhir (may Allah have mercy on him) narrated that there was consensus on it being obligatory, and he regarded the view of the literalists (dhaahiri) – who said that zakah is not obligatory on [trade goods] – as being an odd view that went against scholarly consensus.
Shaykh al-Islam (may Allah have mercy on him) said: The four imams and the rest of the ummah – except those who held odd views – are agreed that it is obligatory  to give zakah on trade goods, whether the trader is a resident or a traveller, and whether he is holding goods – meaning one who buys goods when they are cheap then stores them until such time as prices rise – or is a retailer like the traders in shops, and whether the trade goods are brand-new garments or second-hand clothes; or food such as crops, fruits, condiments and so on; or vessels such as pottery and the like; or slaves; or animals such as horses, mules, donkeys, sheep that he feeds, and so on. Trade goods constitute most of the hidden wealth of people, as livestock constitute most of their visible wealth. End quote.
Majmoo‘ Fatawa Ibn ‘Uthaymeen (25/45).
And Allah knows best.