While Entering the Mosque One has to enter with his right leg.
Salavaat to be recited while entering the Mosque:
Allahumaf Thah LeeAbvaaba Rahmathika
Meaning: Ya Allah open Your gates of Mercy for me.
While Leaving the Mosque One has to Leave with his left leg.
Dua to be recited on leaving the mosque:
Allahumma Innee As-Alukka Min-Fal-Lika VaRahmathika
Meaning: Ya Allah I am leaving with the hope of aquiring YOUR blessings.
Islam is the only religion that teaches disciplines(sunnah) in all the activities we do in our day-to-day life from drinking water to using the toilet.None other religions teach us these things. Allah also give us blessings for leading a life in a sunnah manner...Prophet Muhammad (pbuh) said in the following hadith, "At the time of digression in my Ummah whoever practices my Sunnah, he will get the reward of 100 Martyrs"(Mishqaath).