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but with breaks in between, and you can get up for voluntary prayer,
but you should also sleep. Fast three days a month, and as the
value of a good deed is tenfold this is equal to fasting for ever.‟ I
said, „I am strong enough to do better than that.‟ He said, „Then fast
one day out of every three.‟ I said. „I am strong enough to do even
better than that.‟ He said, „Well, fast one day and not the next. This
was the fast of David and it is the most fine.‟ I said, „I am strong
enough to do better than that.‟ The Prophet, praise and peace be
upon him, replied, „There is nothing better than this.‟ Now I wish that
I had accepted the advice of the Prophet, praise and peace be upon
him, that I fast three days a month. This would be dearer to me than
my children and my wealth.”

We are also informed:

“I have been told that you observe the fast every day and stand for
voluntary prayer throughout the night? I said, „That is so, O
Messenger of Allah, praise and peace be upon him.‟ He said, „Do
not do this. Fast and then leave it; sleep and then stand in prayer.