Narrated 'Ubadah bin As-Samit:
That the Prophet (ﷺ) said: Gold for gold, kind for kind; silver for silver, kind for kind; dried-dates for dried-dates, kind for kind; wheat for wheat, kind for kind; salt for salt, kind for kind; and barley for barley, kind for kind. Whoever increases or seeks an increase, then he dealt with Riba. Sell gold for silver as you wish, hand to hand; and sell wheat for dried-dates as you wish, hand to hand; and sell barley for dried-dates as you wish, hand to hand.
[He said:] There are narrations on this topic from Abu Sa'eed, Abu Hurairah, Bilal, And Anas.
[Abu 'Eisa said:] The Hadith of 'Ubadah bin As-Samit is Hasan Sahih. Some of them reported this Hadith from Khalid, with this chain, and he said: Sell wheat for barley as you wish, hand to hand.
Some of them reported this Hadith from Khalid, from Abu Qilabah, from Ash'ath, from 'Ubadah from the Prophet (ﷺ). In that Hadith, they added that Khalid said: Abu Qilabah said: Sell wheat for barley as you wish, hand to hand.
This Hadith is acted upon according to the people of knowledge, they do not think that one may sell wheat for wheat except when it is the same kind for the same kind, and (the same for) barely in exchange for barley, kind for kind. When the items are themselves different, then there is no harm in one being more than the other if it is hand to hand. This is saying of most of the people of knowledge among the Companions of the Prophet (ﷺ) and others. It is the view of Sufyan Ath-Thawri, Ash-Shafi'i, Ahmad, and Ishaq. Ash-Shafi'i said: And the proof for that is the saying of the Prophet (ﷺ): 'Sell barley for wheat as you wish, hand to hand.'
[Abu 'Eisa said:] Some of the people of knowledge considered it disliked that wheat be sold for barely unless it was kind for kind. This is the view of Malik bin Anas, but the first view is more correct.