Musnad Ahmad

It is narrated from Hazrat Abu Umamah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: When a Muslim servant hears the call to prayer and stands up for ablution, then as soon as the first drop of water falls on his hands, his sins begin to be forgiven. When he rinses his mouth, puts water into his nose, and cleans his nose, the sins of his tongue and lips are removed with the first drop of water. When he washes his face, the sins of his eyes and ears are removed with the first drop of water. And when he washes his hands up to the elbows and his feet up to the ankles, all his previous dangerous sins are forgiven, and he becomes as free from sin as he was at the time of his birth. And when he stands for prayer, it becomes a means of raising his ranks, and if he sits, he sits forgiven.