original site of Adam's altar when the angel Jibrail revealed it to him. Ibrahim ordered his son Ismael – who in Muslim belief is an ancestor of Muhammad – to build a new temple, the Kaaba, into which the stone was to be embedded. Another tradition says that the Black Stone was originally an angel that had been placed by God in the Garden of Eden to guard Adam. The angel was absent when Adam ate the forbidden fruit and was punished by being turned into a jewel – the Black Stone. God granted it the power of speech and placed it at the top of Abu Qubays, a mountain in the historic region of Khurasan, before moving the mountain to Mecca. When Ibrahim took the Black Stone from Abu Qubays to build the Kaaba, the mountain asked Ibrahim to intercede with God so that it would not be returned to Khurasan and would stay in Mecca. According to some scholars, the Black Stone was the same stone that Islamic tradition describes as greeting Muhammad before his prophethood. This led to a debate about whether the Black Stone's greeting comprised actual speech or merely a sound, and following that, whether the stone was a living creature or an inanimate object. Whichever was the case, the stone was held to be a symbol of prophethood. A hadith records that, when the second Caliph Umar ibn al-Khattab (580–644) came to kiss the stone, he said in front of all assembled: "No doubt, I know that you are a stone and can neither harm anyone nor benefit anyone. Had I not seen Allah's Messenger [Muhammad] kissing you, I would not have kissed you." In the hadith collection Kanz al-Ummal, it is recorded that Ali responded to Umar, saying, "This stone (Hajar Aswad) can indeed benefit and harm. ... Allah says in Quran that he created human beings from the progeny of Adam and made them witness over themselves and asked them, 'Am I not your creator?' Upon this, all of them confirmed it. Thus Allah wrote this confirmation. And this stone has a pair of eyes, ears and a tongue and it opened its mouth upon the order of Allah, who put that confirmation in it and ordered to witness it to all those worshippers who come for Hajj." Muhammad Labib al-Batanuni, writing in 1911, commented on the practice that the pre-Islamic practice