عن كعب بن عجرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال : إذا توضأ أحدكم فأحسن وضوءه ثم خرج عامدا إلى المسجد فلا يشبكن بين أصابعه فإنه في صلاة (سنن الترمذي رقم 386)

Hazrat Ka‘b bin ‘Ujrah (radhiyallahu ‘anhu) reports that Rasulullah (sallallahu ‘alaihi wasallam) said, “When anyone of you performs his wudhu in the proper manner, and thereafter proceeds to the Musjid, then he should not intertwine his fingers (i.e. he should observe the etiquettes of salaah. As though) he is already in salaah.” (i.e. when he has begun receiving the reward of a person performing salaah from the time he has set out, then he should observe the etiquettes the salaah) 

4. One should not enter the Musjid without wudhu.

عن أبى هريرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال : لا يزال العبد فى صلاة ما كان فى مصلاه ينتظر الصلاة تقول الملائكة اللهم اغفر له اللهم ارحمه حتى ينصرف أو يحدث فقيل ما يحدث قال يفسو أو يضرط (سنن أبي داود رقم 471)

Hazrat Abu Hurairah (radhiyallahu ‘anhu) reports that Rasulullah (sallallahu ‘alaihi wasallam) said, “As long as one remains on his musallah awaiting salaah, he receives the reward of one who is in salaah. The angels continue to make du‘aa for him, ‘O Allah, forgive him, O Allah, have mercy on him’. He continues receiving reward until the time he leaves the Musjid or breaks his wudhu (in the Musjid).” A Sahaabi (radhiyallahu ‘anhu) asked, “How does he break his wudhu?” Rasulullah (sallallahu ‘alaihi wasallam) replied, “Through passing wind.”

5. Apply ‘itr before coming to the Musjid.

عن أبي سعيد الخدري رضي الله عنه أن رسول الله صلى الله عليه وسلم قال : غسل يوم الجمعة على كل محتلم وسواك ويمس من الطيب ما قدر عليه (صحيح مسلم رقم 847)

Hazrat Abu Sa‘eed Khudri (radhiyallahu ‘anhu) reports that Rasulullah (sallallahu ‘alaihi wasallam) said, ““Every baaligh person should perform ghusal on the day of Jumu‘ah, make miswaak and apply any ‘itr that he is able to apply.”

6. Remove any foul smell from one’s body, clothing or mouth before entering the Musjid e.g. after eating onions.

عن جابر رضي الله عنه قال : قال رسول الله صلى الله عليه وسلم : من أكل من هذه الشجرة المنتنة فلا يقربن مسجدنا فإن الملائكة تتأذى مما يتأذى منه الإنس (مسلم رقم 564)

Hazrat Jaabir (radhiyallahu ‘anhu) reports that Rasulullah ((sallallahu ‘alaihi wasallam) said, “Whoever eats from this foul-smelling tree, then he should not come close to our Musjid, for the angels are inconvenienced through the bad odour of those things which you are inconvenienced through.”