9. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Muhammad ibn Sahl from his father who has said the following: “I once asked abu al-Hassan , about the case of a man for whom the farmers cultivate saffron and guarantee to give him a certain amount by the weight of dirham for every Jirib (a certain unit of measurement) that is cultivated and then it may produce less thus, he is in loss or may produce more, thus, he gains. He (the Imam) said,

‘It is not unlawful if they mutually agree.’”