Ishaq ibn Mansur narrated to me; Abdur-Rahman ibn Mahdi narrated to us, from Hammad ibn Zayd, from Yahya ibn ʿAtiq, from Ibn Sirin, who said:

“It used to be said, ‘How astonishing—how can a merchant conduct his trade?’ Yahya would reply, ‘By being truthful and by doing this and that.’

Muhammad continued: ‘When Yahya later went into business with me, he said, “My brother, there is nothing in this trade that does not give me misgivings.”’

He added, ‘I then told Humayd ibn Abdur-Rahman what had happened, and Muhammad remarked, “Only now has he come to understand (fiqh).”’