Sunan Abi Dawud 467
سنن أبي داود#467SahihAbu Qatadah reported the Messenger of Allah (May peace be upon him) as saying; when any one of you enters the mosque, he should pray two RAKAHS before sitting down
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 ZaiSahih Bukhari (444) Sahih Muslim (714)
In-book reference: 2:77