Mukhtasar Bukhari

Umm al-Mu’minin Aisha Siddiqa (may Allah be pleased with her) says that when the Prophet Muhammad (peace and blessings be upon him) used to observe voluntary fasts, he would fast so much that we would think he would never stop fasting, and when he would stop, he would stop so much that we would think he would never fast again. And I did not see the Messenger of Allah (peace and blessings be upon him) observe a full month of fasting except in Ramadan, and I did not see him fast in any month more than in Sha’ban.

Narrated from Ummul Momineen Aisha Siddiqa (may Allah be pleased with her) that the Prophet Muhammad (peace and blessings be upon him) did not observe (supererogatory) fasts in any month more than in Sha’ban; rather, it seemed as if he spent almost the whole of Sha’ban fasting. She further says that the Prophet (peace and blessings be upon him) used to say: “O people! Take upon yourselves only as much worship as you can bear, for Allah does not tire (of giving reward) until you tire (of worship), and the best prayer in the sight of the Prophet (peace and blessings be upon him) was that which was performed regularly, even if it was little. And whenever the Prophet (peace and blessings be upon him) performed a prayer, he would make it regular.”