Is grain, such as wheat and barley, that is sold on credit for a period of a month regarded as Riba (usury)?
If wheat and barley are sold in return for an equivalent of their very genus, they should be equal in quantity, and the exchange should take place in the same session. If they are not sold in return for an equivalent of the same genus - as when wheat is sold in return for barley or corn -, variation in the exchanged quantities is permitted, and the exchange should take place in the same session. If they are sold in return for money, either the price or the sold item is permitted to be delayed on condition that either of them should be collected in the same session. (Part No. 11; Page No. 122) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family and Companions.