Chapter on Sales

Al-Ala' narrated from Muhammad bin Muslim, from one of the imams (peace be upon them), who said: I asked Imam عليه السلام about a man who gives grain to a miller and agrees with him to receive ten measures of flour for every ten measures of grain. Imam عليه السلام said: "No." I then asked: "What about a man who gives sesame seeds to an oil presser and guarantees to receive a specified amount of oil for each measure?" Imam عليه السلام said: "No."