The illustrious Tabi’ee; Sa’eed ibnul Musayyab (rahimahullah) said:
One who is seated in the Masjid, is actually seated in the company of Allah Ta’ala.
(Tafsir Qurtubi, vol.6 pg.560)
The renowned Mufassir (commentator of Quran) Imam Abu ‘Abdillah Al-Qurtubi (rahimahullah) has listed the following etiquettes of the Masjid:
DO’S in Masjid:
1.1. Upon entering the Masjid, one should greet the people with Salam. (This only applies when those present are not offering salah, or reciting Quran. If they are occupied in the above, one should not greet them)
1.2. If there is no one present, one should say:
Assalamu’alaini wa’ala ‘ibadillahis salihin
2. Before being seated one should offer two rak’ats of Tahiyyatul Masjid. (The makruh-forbidden- times of salah are excluded in this etiquette)
The Makruh times of salah are:
a) After Fajr till 15 minutes after sunrise, (Sahih Bukhari, hadith: 586 & Sahih Muslim, vol.1 pg.275)
b) At mid-day. (Sahih Muslim, vol.1 pg.276)
c) After ‘Asr till sunset. (Sahih Bukhari, hadith: 586)
d) During the Friday khutbah (sermon) (Nasbur rayah, vol.2 pgs.201-201)
3. One should keep the Masjid free of filth, children and insane people (as they do not understand the sanctity of the Masjid)
4. One should remain engaged in the dhikr (remembrance) of Allah as much as possible.
DONT’S of the Masjid:
1. One should not carry out any business transaction in the Masjid. (even by means of the cellphone)
2. One should not draw a weapon in the Masjid.
3. One should not make an announcement for the search of lost items.
4. One should not raise his voice. (This includes cellphone rings, beepers, pagers etc)
5. One should not discuss worldly affairs. (even via a phone call or sms!)
6. One should not climb over the shoulders of those already seated in the rows. (to get to the front. This disrupts the congregation)
7. One should not force his way into a row wherein there isn’t enough space.
8. One should not cross in front of someone offering salah.
9. One should avoid spitting or blowing his nose in the Masjid.
10. One should not crack the fingers. (as this is a futile act and it causes disturbance)
11. One should not play/fiddle with any part of the body.
After enlisting these 15 etiquettes, ‘Allamah Qurtubi (rahimahullah) writes:
“Whoever abides by these has fulfilled the right of the Masjid, and it will be a place of security and protection for him against Shaytan.
(Tafsir, Qurtubi, vol.6 pg.560; Darul Hadith, Cairo)
Note: Take notice of the fact that there are more DON’TS than DO’S in the masjid. This is so its sanctity be maintained….
May Allah Ta’ala inspire us all to uphold the respect for his House. Ameen.
Taken From: http://www.al-miftah.com/2014/03/14/etiquettes-of-the-masjid/