It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: A person who waits for one prayer after another is like a warrior whose horse stands ready on its side in the path of Allah. For him, Allah's angels continue to pray for forgiveness as long as he does not lose his ablution or stand up from there, and this will be counted as the greatest vigilance (ribat akbar) among the most important forms of guarding.