"أفضل الصيام بعد رمضان شهر الله المحرم، وأفضل الصلاة بعد الفريضة صلاة الليل"
Abu Hurairah (May Allah be pleased with him) reported: The Messenger of Allah (ﷺ) said, "The best month for observing Saum (fasting) after Ramadan is Muharram, and the best Salat after the prescribed Salat is Salat at night." [Muslim] .