Seek forgiveness from Allah before entering or leaving a place of worship ; Show respect towards Prophet Muhammad by saying salat & salam upon him whenever his name is mentioned or thought of ; Ask God sincerely for His mercy & blessings .

This hadith is about Prophet Muhammad's prayer to Allah for forgiveness and mercy when entering and exiting the mosque. The Prophet would say "O pardon my sins, and open the gates of Your mercy/blessings for me" as he entered or exited. This teaches us that we should always seek forgiveness from Allah before we enter or leave any place of worship. It also shows us that we should always be humble in our prayers to God, asking Him to forgive us for our wrongdoings. We should also remember that God's mercy is infinite; He will always forgive us if we sincerely ask Him to do so. Furthermore, this hadith reminds us of how important it is to show respect towards Prophet Muhammad by saying salat and salam upon him whenever his name is mentioned or thought of.