Sunan Abi Dawud 4673
سنن أبي داود#4673SahihAbu Hurairah reported the Messenger of Allah (May peace be upon him) as saying :I shall be pre-eminent among the descendants of Adam, the first from whom the earth will be cleft open the first intercessor, and the first whose intercession will be accepted
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Zubair Ali ZaiSahih Muslim (2278)
In-book reference: 42:78