Ishaq bin Mansur al-Kausaj إسحاق بن منصور بن بهرام - الكوسج · The Book of Financial Transactions

the Prophet forbade selling the harvest for a number of years (in advance.)

This is what I have found on this topic.

"Go and buy a young camel for him." He came and said: "I could only get a Raba camel of good quality." He said: "Give it to him, for the best of the Muslims is the one who is best in repaying."