Hadith 8:2824
Abu Bakr narrated to us, he said: Ubayd Allah ibn Musa narrated to us, from Musa ibn Ubaydah, he said: I asked Muhammad ibn Ka’b about it. He said: The jurists differed regarding it; so if you are strict, it is good, and if you grant a concession, it is good.
حدثنا أبو بكر قال نا عبيد الله بن موسى عن موسى بن عبيدة قال سألت عنه محمد بن كعب فقال اختلف فيه الفقهاء فإن شددت فحسن وإن رخصت فحسن