Sahih Muslim Book 7, Hadith Number 3124.

Chapter : Staying at Dhu’l-Halaifa and observing of prayer there, while returning from Hajj or Umra.

Salim b. Abdullah b. Umar reported on the authority of his father (Allah be pleased with them) that Allah’s Apostle (may peace be upon him) came to Dhu’l-Hulaifa in the heart of the valley at the fag end of the night, and it was said to him: It is a blessed stony ground. Musa (one of the narrators) said: Salim made his came) halt at the mosque where ‘Abdullah made his camel halt as seeking the place of stay of Allah’s Messenger (may peace be upon him). It is, in fact, situated at a lower plain than the mosque, which stands in the heart of the valley, and it is between it (the mosque) (and Qibla) that that place (where Allah’s Apostle used to get down for rest and prayer) is situated.