The Hacer-ul Esved (Hajar al-Aswad) is set in the eastern corner of the Kabe and marks the starting point of Tavaf. Islamic tradition holds it was sent down from Paradise. Hz. Peygamber Muhammad (sallallahu aleyhi ve sellem) kissed it during his Tavaf. When kissing is not possible due to crowds, hacilar point toward it and say 'Allahu Akbar.'
Islamic tradition holds that the Hacer-ul Esved was sent down from Paradise. According to a hadith narrated by Ibn Abbas, Hz. Peygamber Muhammad (sallallahu aleyhi ve sellem) said, 'The Hacer-ul Esved descended from Paradise whiter than milk, but the sins of the sons of Adam turned it black' (Tirmidhi). The stone was placed in its current position by Prophet Ibrahim when he built the Kabe with his son Ismail. When the Quraysh rebuilt the Kabe in 605 CE, a dispute arose over which clan would have the honor of placing the stone in the new wall. The young Muhammad resolved the conflict by placing the stone on a cloth that representatives of each clan lifted together, then setting it in place with his own hands — an event that predated his prophethood.
The Hacer-ul Esved is not a single piece but consists of several fragments bound together by a silver frame. The visible surface is approximately 30 centimeters in diameter. Its fractured state is attributed to various historical incidents: it was reportedly broken during the Quraysh rebuilding, cracked by a stone catapult during the siege of Mekke by the Umayyads in 683 CE, and was stolen by the Qarmatians in 930 CE, who took it to their capital in Bahrain for 22 years before returning it. Each of these events contributed to the fragmentation of the original stone. Modern geological analysis suggests the stone may be of meteoritic origin, though this remains debated.
The Hacer-ul Esved marks the starting and ending point of each circuit of Tavaf. The sunnah is to kiss the stone at the beginning of each circuit, following the practice of Hz. Peygamber Muhammad (sallallahu aleyhi ve sellem). Umar ibn al-Khattab famously said, 'I know that you are a stone and can neither benefit nor harm. Had I not seen Hz. Peygamber kiss you, I would not have kissed you' (Bukhari). When kissing is impossible due to crowd density — which is the reality for most hacilar most of the time — the alternative is to touch it with the hand and then kiss the hand, or to simply face it, raise the right hand toward it, and say 'Allahu Akbar.' Causing harm to others while trying to reach the stone is explicitly condemned by scholars.
The Hacer-ul Esved serves as a witness to the covenant between Allah and humanity. According to some scholarly interpretations, it represents the primordial covenant (mithaq) mentioned in Kur'an-i Kerim (7:172) when Allah asked all souls, 'Am I not your Lord?' and they responded, 'Yes, we bear witness.' Hz. Peygamber said that the stone will come on the Day of Judgment with two eyes and a tongue, testifying on behalf of those who touched it with sincerity (Tirmidhi, Ibn Majah). While Muslims do not worship the stone — as Umar's statement makes clear — they honor it as a sign and a connection to the prophetic tradition of Ibrahim and Muhammad (peace be upon them both).