1. Every musalli has an equal right in the use of the musjid and its items. Hence, it is not permissible for one to reserve any place or item of the musjid for himself.
عن عبد الرحمن بن شبل رضي الله عنه قال نهى رسول الله صلى الله عليه وسلم عن نقرة الغراب وافتراش السبع وأن يوطن الرجل المكان في المسجد كما يوطن البعير (سنن أبي داود، الرقم: 862)
Hazrat Abdur Rahmaan bin Shibl (radhiyallahu anhu) reports, “Rasulullah (sallallahu alaihi wasallam) prohibited (making sajdah like) the pecking of a crow (i.e. making sajdah extremely swiftly), and spreading one’s forearms on the ground (during sajdah) in the manner a predatory animal sits down, and reserving a place for oneself (in the musjid) as a camel reserves a place for itself.”
2. It is not permissible to make a person move from his place in the musjid so that someone else can sit in his place.
عن ابن عمر رضي الله عنهما عن النبي صلى الله عليه وسلم أنه نهى أن يقام الرجل من مجلسه ويجلس فيه آخر ولكن تفسحوا وتوسعوا (صحيح البخاري، الرقم: 6270)
Hazrat Ibnu Umar (radhiyallahu anhuma) reports that Hazrat Rasulullah (sallallahu alaihi wasallam) had prohibited that a man be made to move from his place (in the musjid) and another man sit in his place. Rather, the people should make place (for those who arrive if it is possible to make place for them).
3. Do not crack your knuckles while in the musjid. Similarly, do not intertwine your fingers while seated in the musjid.
عن مولى لأبي سعيد الخدري قال بينا أنا مع أبي سعيد رضي الله عنه وهو مع رسول الله صلى الله عليه وسلم إذ دخلنا المسجد فإذا رجل جالس في وسط المسجد محتبيا مشبكا أصابعه بعضها في بعض فأشار إليه رسول الله صلى الله عليه وسلم فلم يفطن الرجل لإشارة رسول الله صلى الله عليه وسلم فالتفت إلى أبي سعيد فقال إذا كان أحدكم في المسجد فلا يشبكن فإن التشبيك من الشيطان وإن أحدكم لا يزال في صلاة ما كان في المسجد حتى يخرج منه (مجمع الزوائد، الرقم: 2047 ، الترغيب والترهيب، الرقم: 450)
The freed slave of Hazrat Abu Sa’eed Khudri (radhiyallahu anhu) reports, “On one occasion, while I was with Abu Sa’eed (radhiyallahu anhu) and he was with Rasulullah (sallallahu alaihi wasallam), we entered the musjid and saw a man seated in the centre of the musjid. This man was sitting on his buttocks in the manner that his knees were raised, and his arms were wrapped around his knees, with the fingers of both his hands intertwined. Rasulullah (sallallahu alaihi wasallam) gestured towards this man (to draw his attention), but the man did not notice the gesture of Rasulullah (sallallahu alaihi wasallam). Rasulullah (sallallahu alaihi wasallam) thus turned towards Abu Sa’eed (radhiyallahu anhu) and said, ‘When any one of you is in the musjid, then he should not intertwine his fingers, as intertwining the fingers is from Shaitaan. As long as you remain in the musjid waiting for salaah, you will receive the reward of salaah, as though you are in salaah, until you leave the musjid (hence, when intertwining the fingers during salaah is against the etiquette of salaah, then one should also not intertwine the fingers when waiting for salaah).’”
4. Do not mess or soil the musjid e.g. by spitting in the musjid or blowing one’s nose and allowing the dirt to fall onto the ground.
عن أبي ذر رضي الله عنه قال قال رسول الله صلى الله عليه وسلم عرضت علي أعمال أمتي حسنها وسيئها فوجدت في محاسن أعمالها الأذى يماط عن الطريق ووجدت في مساوئ أعمالها النخاعة تكون في المسجد لا تدفن (صحيح مسلم، الرقم: 553)
Hazrat Abu Zar (radhiyallahu anhu) reports that Hazrat Rasulullah (sallallahu alaihi wasallam) said, “The good deeds and evil deeds of my Ummah were presented before me. I found that among the good deeds is for one to remove a harmful object from the pathway, and I found that among the evil deeds is (for one to leave) the dirt of one’s nose (which had fallen to the floor) in the musjid without burying it.”
عن أنس رضي الله عنه قال قال رسول الله صلى الله عليه وسلم البزاق في المسجد خطيئة وكفارتها دفنها (صحيح البخاري، الرقم: 415)
Hazrat Anas (radhiyallahu anhu) reports that Hazrat Rasulullah (sallallahu alaihi wasallam) said, “To spit in the musjid is a sin, and its compensation is to bury it (with sand).” (This was at the time when the salaah in the musjid used to be performed on the bare ground.)
5. Do not distribute parcels, hampers and other goods in the musjid. Similarly, do not make the musjid a drop off point for collecting parcels.