It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Whoever buys a goat whose udder has been tied (as a deception), then he should either keep the animal with himself (and resolve the matter) or return the animal to its owner and along with it give one sa’ of dates.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 9559