Jami` at-Tirmidhi 1236

Narrated Ibn 'Umar: "The Messenger of Allah (ﷺ) prohibited selling the Wala' and conferring it." [Abu 'Eisa said:] This Hadith is Hasan Sahih. We do not know of it except as a narration of 'Abdullah bin Dinar, from Ibn 'Umar. This Hadith is acted upon according to the people of knowledge. Yahya bin Sulaim reported this Hadith from 'Ubaidullah bin 'Umar, from Nafi' from Ibn 'Umar from the Prophet (ﷺ), saying "That he prohibited selling the Wala' and conferring it." But this is mistake from Yahya bin Sulaim. Because 'Abdul Wahhab Ath-Thaqafi, 'Abdullah bin Numair and others reported it from 'Ubaidullah bin 'Umar, from Ibn 'Umar, from the Prophet (ﷺ). And this is more correct than the narration of Yahya bin Sulaim