Bukhari

Hadith Commentary:
(1)
There is brevity in this hadith.
The detailed hadith has already been mentioned earlier, in which it is prohibited to go out to receive those bringing grain for sale.
(Sahih al-Bukhari, al-Buyu', Hadith: 2158)
Some narrations indicate that it is permissible to purchase grain from caravan traders, while other hadiths prohibit it. The reconciliation between them is as follows: if this sale causes harm to the market traders, then it is prohibited; if it does not cause harm, then it is permissible. Thus, in Sahih Muslim, it is stated that the Messenger of Allah (sallallahu alayhi wa sallam) said:
"Do not go ahead to purchase grain from caravan traders. If someone has made such a sale, then when the seller reaches the market, he has the choice to either uphold the sale or annul it."
(Sahih Muslim, al-Buyu', Hadith: 3823(1519))
(2)
Despite the prohibition of this sale in this hadith, the seller has been given the option to annul it.
It is understood from this that the sale is valid; otherwise, what would be the meaning of the option (of annulment)? If the sale were invalid, both the seller and the buyer would be compelled to terminate it. However, Imam Bukhari (rahimahullah) has declared this type of sale to be outright rejected in unequivocal terms.