Book of Defects
Chapter: The Udder-Bound Animal (muṣarrāh)

When someone purchases a ewe, cow, or she-camel that has been udder-bound and is unaware of the taṣriya, he may, after milking it, choose the better of two options: if he wishes, he keeps it; if he wishes, he returns it along with one sāʿ of dates.

Taṣriya is to withhold milking the sheep, camel, or cow until its udder swells, so the animal is sold in that condition. The buyer then milks it two or three times. The first milking is the milk produced because of the taṣriya. He then milks it once or twice more to test it; when the yield and the udder diminish, he realizes it is muṣarrāh and decides to return it. If he does so, he must send it back with one sāʿ of dates to compensate for the taṣriya milk—unless wheat is the predominant staple food, as in Egypt, in which case, according to Mālik, he returns one sāʿ of wheat instead.

Ibn Shihāb said: He returns it with one sāʿ of dates or one mudd of barley.

Ibn al-Qāsim said: If the buyer milks it a second time and then wishes to return it, he may, for the true measure of its milk is only known by the second milking. But if he milks it a third time, that constitutes acceptance of its defect.