Hazrat Muhammad bin Abdur Rahman narrates that when Hazrat Abdullah bin Salam would enter the mosque, he would send salutations upon the Noble Prophet (peace and blessings be upon him) and recite this supplication: "O Allah! Open for me the doors of Your mercy." And when he would leave the mosque, he would send salutations upon the Noble Prophet (peace and blessings be upon him) and seek refuge from Satan.