Encyclopedia of Prophetic Hadiths

"Whoever fasts a day in the way of Allah, Allah will keep his face away from the Fire seventy falls."

"You fast continuously and stand in prayer at night?" I said: Yes. He said: "If you do that, your eyes will become weak, and your soul will become weary. No fasting counts for the one who fasts continuously. Fasting three days is like fasting the entire year". I said: Indeed, I am capable of more than that. He said: "Then fast the fast of Dāwūd (David) (peace be upon him); he used to fast one day and break his fast the next day, and he would not flee when facing the enemy."

My close friend (may Allah's peace and blessings be upon him) advised me with three: fasting three days of every month, the two Rak‘ahs of Duha, and performing Witr before I sleep."