"The Messenger of Allah said: '(Exchanging) gold for silver is Riba unless it is done on the spot. (Exchanging) dates for dates is Riba unless it is done on the spot. (Exchanging) wheat for wheat is Riba unless it is done on the spot. (Exchanging) barley is Riba unless it is done on the spot."'
Sunan an-Nasa'i Book 44, Hadith 110
← Previous Hadith "Bilal brought some Bami dates to the Messenger of Allah and he said: 'What is this? 'He said: 'I bought a Sa of them for two Sas. The Messenger of Allah said: "O! The essence of Riba, do not approach it."'

Sunan an-Nasa'i Book 44, Hadith 109 Next Hadith → "The Messenger of Allah said: 'Dates for dates, wheat for wheat, barley for barley, salt for salt, exchanged hand to hand. Whoever gives more or takes more has engaged in Riba unless they are of different types."

Sunan an-Nasa'i Book 44, Hadith 111