من لا يحضره الفقيه, volume 3, page 230

Hadith.3850 - Al-Hasan bin Mahbub narrated from Abu Wallad who said: I asked Abu Abdillah (as) about a man who owns sheep that produce a large quantity of milk every day. What do you say about purchasing five hundred ritls of milk for a specified amount of dirhams, taking a certain amount from it each day until he fulfills what he purchased? Imam (as) said: "There is no harm in this and similar transactions."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.

Hadith.3851 - Al-Hasan bin Mahbub narrated from Rifa'ah Al-Nakhas who said: I said to Abu Abdillah (as), "I bargained with a man over a bondwoman, and he sold her to me based on my judgment. I took possession of her on that basis, then I sent him one thousand dirhams and said to him, 'Here are one thousand dirhams based on my judgment over you.' But he refused to accept them from me, and I had already touched her before sending him the payment." Imam (as) said: "I see that the bondwoman should be appraised at a fair value. If her value is more than what you sent him, then you must pay him the difference. However, if her value is less than what you sent him, then the surplus belongs to him." I said: "May I be your ransom, what if I find a defect in her after having touched her?" Imam (as) said: "You do not have the right to return her, but you are entitled to claim the difference between her value when healthy and her value with the defect from him."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.