‘Umar b. al-Khattab used to prohibit (men) to enter through the door reserved for women.
Sunan Abi Dawud Book 2, Hadith 74
← Previous Hadith This tradition has been reported by 'Umar b. al-Khattab through a different chain of narrators. He narrated it to the same effect and that is more correct.

Sunan Abi Dawud Book 2, Hadith 73 Next Hadith → 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.

Sunan Abi Dawud Book 2, Hadith 75