سورة Al-Baqarah ( The Cow ) - الآية 125

And (remember) when We made the House (the Ka'bah at Makkah) a place of resort for mankind and a place of safety. And take you (people) the Maqam (place) of Ibrahim (Abraham) [or the stone on which Ibrahim (Abraham) stood while he was building the Ka'bah] as a place of prayer (for some of your prayers, e.g. two Rak'at after the Tawaf of the Ka'bah at Makkah), and We commanded Ibrahim (Abraham) and Isma'il (Ishmael) that they should purify My House (the Ka'bah at Makkah) for those who are circumambulating it, or staying (I'tikaf), or bowing or prostrating themselves (there, in prayer).