Mosquee etiquette: rights and manners

The mosque has expressly fixed rights: the Prophet (may Allah's peace and blessings be upon him) taught:

When one of you enters the mosque, let him say: O Allah, open for me the doors of Your mercy; when he exits: O Allah, I ask Your grace.Muslim 713

At entry

• Entering with the right foot with the opening invocation, exiting with the left foot with the exit invocation.
• Praying the two greeting rak'as (tahiyyat al-masjid) before sitting (al-Bukhari 444); if the iqama is announced, one prays the rak'a at hand per the schools.
• Being perfumed and wearing one's finest clothes; the woman presents herself modestly without perfume per the reported Sunna (Muslim 898).

While present

• Not chatting about everything: the mosque is for worship, dhikr and learning.
• Not passing in front of the worshiper: the Prophet fixed the crossing point (musalla or barrier, al-Bukhari 511); the harm of crossing is expressly noted.
• Making no noise: silence the phone, lower the voice, not shouting for the absent (Muslim 667 on forbidding shouting to gather).
• Not chasing children: the Prophet carried Umama during prayer (al-Bukhari 516); children hold a mosque welcome right.

The mosque's rights

Cleaning it, lighting it, joining its maintenance is charity, a right fixed by the prophetic order reported from 'Aisha: build mosques within houses, clean them and perfume them; al-Albani (Ahkam al-Masajid, pp. 585-588) adds Umar's practice of fumigating the Prophet's mosque each Friday; the Prophet praised the man who poured water into the mosque (Abu Dawud 1104). Selling there, announcing a lost item or seeking the lost item there: formally forbidden per Ibn Uthaymin (Fatawa Nur ala ad-Darb): "may Allah not prosper your trade", mosques are not built for that; Muslim 568's hadith shows its gravity.

Practical note

Arriving early, parking properly, not blocking entrances: mosque etiquette begins in the street. The neighborhood mosque is the community's living room: respect the neighbors as at home.