Mukhtasar Muslim

Abu Huraira (may Allah be pleased with him) reports that the Messenger of Allah (peace and blessings be upon him) said to Bilal after the morning prayer: "O Bilal! Tell me about the deed you have done in Islam for which you have the greatest hope of reward, for I heard the sound of your footsteps ahead of me in Paradise last night." Bilal (may Allah be pleased with him) replied: "I have not done any deed in Islam for which I have greater hope of benefit except that whenever I perform ablution, whether by night or by day, I pray as much as Allah has destined for me with that ablution."