He said that when God’s messenger was asked about fasting on Monday he said, “On it I was born and on it the revelation was first sent down to me.”* *The meaning seems to be that as this day is so distinguished, one could not choose a better one. Muslim transmitted it.
Hadith Referenceمشكوة المصابيح / كتاب الصوم / 2045
Hadith Gradingالألبانی:صَحِيح | زبیر علی زئی:صحيح
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «رواه مسلم (198 / 1162)»