'When one of you performs Wudhu and perfects it and then goes to the Masjid, let him not intertwine his fingers, for indeed he is in prayer.'(Abu Dawood) *It is lawful for one to eat and drink in the Masjid. Abdullah b. al-Harith b. Juz' az-Zubaidi () said:
'We used to eat bread and meat in the Masjid of the Prophet () when the Messenger of Allah () was alive.' (Ibn Majah) *It is lawful for one to recite lines of poetry in the Masjid. Has'san b. Thabit () used to say a few lines of poetry in front of the Messenger of Allah (). (Bukhari) *It is lawful for one to play with spears in the Masjid. A'ishah () said: 'I saw the Messenger of Allah () standing on the pedestal of my door and the Habashah (Ethiopians) were playing in the Masjid; the Messenger of Allah () was covering me with his garment and I was looking at them play in the masjid.' (Bukhari) *It is inappropriate for one to leave the Masjid after the Adthaan has been called, except if one has a valid reason to do so. This is taken from the hadeeth of Abu ash-Sha'thaa () in which he said: 'We were sitting in the Masjid with Abu Hurairah () and the Mu'adthin called the Adthaan and a man got up to leave the Masjid…Abu Hurairah () followed him until he left the masjid and he said: 'As for this individual, he certainly has disobeyed the Messenger of Allah ().'(Muslim) *It is inappropriate for one to decorate the Masjid and etch calligraphy in its walls. The Prophet () said:
