Sahih Muslim Book 6, Hadith Number 2590.

Chapter : Forbiddance to observe perpetual fast and excellence of observing fast on alternate days.

‘Abdullah b. ‘Amr b. al-‘As (Allah be pleased with them) reported that the Messenger of Allah (may peace be upon him) said: ‘Abdullah, don’t be like so and so who observed prayer during the whole night and then abandoned it (altogether).