Mishkat al-Masabih 450

ʿAbd Allāh ibn ʿUmar said: ‘The prayers were initially fifty, ritual bathing after sexual impurity was required seven times, and washing urine from a garment was required seven times. The Messenger of Allah continued to ask until the prayers were set at five, ritual bathing after sexual impurity at once, and washing urine from a garment at once.’ Abū Dāwūd transmitted it.