His friends ask him to buy computers for them and he adds a profit for himself

Can he sell an item to someone who pays for it with a cheque from a riba-based bank?

Ruling on selling iTunes and internet cards for more than their price

Meaning of the hadeeth “Whoever sells a house or piece of land and does not put its price into something similar, will not be blessed therein”

Ruling on selling textbooks that contain pictures

Business sale

Ruling on buying machines by instalments through the bank

Ruling on buying diamonds on the Internet

Developing an iPhone program on a personal computer contrary to the agreement with the Apple company

He sold land to someone for a deferred payment, and that person sold it for a higher price; can the transaction be cancelled because of the loss?