رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 1255
The Book of Virtues
The Desirability of Observing Saum (Fasting) on Monday and Thursday
عَنْ أَبِي قَتَادَةَ رَضِيَ اللَّه عَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ: سُئِلَ عَنْ صوم يوم الاثنين فقال: ذلك يَوْمٌ وُلِدْتُ فِيهِ، وَيَوْمٌ بُعِثْتُ أَوْ أُنْزِلَ علي فِيهِ ((رَوَاهُ مُسْلِم)).
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].
Riyad as-Salihin, 1255