the prayer, he is already regarded as being in prayer.
O Muslim, set out for the mosque early so that you may catch the opening takbir and join the congregation from the very first moment. Keep your steps close together as you walk to the prayer, for that increases your reward. In the Two Ṣaḥīḥs it is related that the Prophet said, “If one of you performs ablution well and then goes out to the mosque, he does not take a single step except that a rank is raised for him by it and a sin is erased.”
When you reach the door of the mosque, enter with your right foot first and say: “In the name of Allah. I seek refuge in Allah the Magnificent, in His Noble Face, and in His Eternal Sovereignty from Satan the accursed. O Allah, send blessings upon Muhammad. O Allah, forgive my sins and open for me the gates of Your mercy.”
When you wish to leave, step out with your left foot first and repeat the same supplication, replacing “and open for me the gates of Your mercy” with “and open for me the gates of Your bounty,” for the mosque is a place of mercy, whereas outside the mosque is the place of sustenance, which is a bounty from Allah.
After entering the mosque, do not sit down until you have prayed two rak‘ahs as the greeting of the mosque, for he said, “When one of you enters the mosque, let him not sit until he has prayed two rak‘ahs.”