It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) said: Whoever recites "Allahu Akbar" thirty-three times, "Subhan Allah" thirty-three times, and "Alhamdulillah" thirty-three times after every prayer, and at the end says: "La ilaha illallah wahdahu la sharika lahu, lahul mulk wa lahul hamd wa huwa 'ala kulli shay'in qadeer," then all his sins will be forgiven, even if they are more than the foam of the sea.