سنن النسائي

'Abduallah bin amr bin Al-'As said: "The Messenger of Allah (ﷺ) heard that I was fasting continually and praying all night." Either he sent for him, or he happened to meet him and he said: "Have I not been told that you fast and never break your fast, and you pray all night? Do not do that, for do that, for your eyes should have a share, your self should have a share, and your family should have a share. Fast and break your fast; pray and sleep. Fast one day out of every ten, and your will have the reward of the other nine." He said: " I am able to do more than that, O Messenger of Allah." He said: "Observe the fast of Dawud then." " I said: 'How did Dawud fast, O Prophet of Allah? He said: 'He used to fast one day, and not the next, and he never fled if he met(the enemy in battle)."' He said: "How can I compare to him, O Prophet of Allah?"