Sunan Abi Dawud 465
سنن أبي داود#465SahihAbu Usaid al-Ansari reported the Messenger of Allah (May peace be upon him) as saying:when any of you enters the mosque he should invoke blessing on the prophet (ﷺ) and then he should say: O Allah, open to me the gates of thy mercy. And when he goes out, he should say: O Allah, I ask thee out of Thine abundance
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
Shuaib Al ArnautSahih
Zubair Ali ZaiIsnaad Sahih Sahih Muslim (713)
In-book reference: 2:75