(2) باب تَحْرِيمِ الرَّضَاعَةِ مِنْ مَاءِ الْفَحْلِ
'A'isha (Allah be pleased with her) reported:
My foster-uncle Abu'l Ja'd (kunya of Aflah) sought permission from me, which I refused. (Hisham said to me that Abu'l-Ja'd was in fact Abu'l-Qu'ais). When Allah's Apostle (ﷺ) came, I ('A'isha) informed him about it. He said: Why did you not permit him? Let your right hand or hand be besmeared with dust.
Reference: Sahih Muslim 1445 h
In-book reference: Book 17, Hadith 11
USC-MSA web (English) reference(deprecated numbering scheme): Book 8, Hadith 3404