Riyad as-Salihin
Riyad as-Salihin 1255
The Desirability of Observing Saum (Fasting) on Monday and Thursday
Arabic hadith text
عن أبي قتادة رضي الله عنه أن رسول الله صلى الله عليه وسلم: سئل عن صوم يوم الاثنين فقال: "ذلك يوم ولدت فيه، ويوم بعثت أو أنزل علي فيه" ((رواه مسلم)).
Translation
Abu Qatadah (May Allah be pleased with him) reported
The Messenger of Allah (ﷺ) was asked about fasting on Mondays. He said, "That is the day on which I was born and the day on which I received Revelation."[Muslim].