As for the corruption of Hajj through intercourse in the vagina, there is no disagreement regarding it. Ibn al-Mundhir said: The scholars have reached a consensus that Hajj is not corrupted by committing any act during the state of ihram except for intercourse. The basis for this is what was narrated from Ibn Umar, that a man asked him, saying: "I have had intercourse with my wife while we were in the state of ihram." He replied: "You have corrupted your Hajj. Depart, you and your wife, with the people, perform the rites that they perform, and exit the state of ihram when they exit it. Then, when the coming year arrives, perform Hajj, both you and your wife, and offer a sacrifice (hady). If you cannot find one, then fast three days during the Hajj and seven when you return." Similar was said by Ibn Abbas and Abdullah ibn Amr (1). We are not aware of anyone in their era who disagreed with them. Their hadith (2) was narrated by al-Athram in his "Sunan" (3), and in the hadith of Ibn Abbas: "They shall separate from where they entered the state of ihram until they complete their Hajj." [Ibn al-Mundhir said: The statement of Ibn Abbas is the highest authority narrated regarding one who has intercourse during his Hajj] (4). This was also narrated from Umar, may Allah be pleased with him. This is the opinion of Ibn al-Musayyab, Ata', al-Nakha'i, al-Thawri, al-Shafi'i, Ishaq, Abu Thawr, and the People of Opinion (Ashab al-Ra'y). There is no distinction between before the Standing (at Arafat) and after it. Abu Hanifa said: If one has intercourse before the Standing, his Hajj is corrupted, but if he has intercourse after it, it is not corrupted, based on the saying of the Prophet, peace and blessings of Allah be upon him: "Hajj is Arafat" (5). Also, it is a situation in which one is safe from the Hajj being missed (fawat), so he is safe from corruption, similar to the state of exiting ihram (tahallul).
(1) In B and M: "Umar". This is an error. (2) Omitted from: M. (3) Their hadith was also narrated by al-Bayhaqi, in: The Chapter on What Corrupts Hajj, from the Book of Hajj. Al-Sunan al-Kubra 5/167, 168. (4) Omitted from: A. (5) Excerpted by Abu Dawud, in: The Chapter on One Who Did Not Catch Arafat, from the Book of Manasik (Rites). Sunan Abi Dawud 1/451, 452. And al-Tirmidhi, in: The Chapter on the Interpretation of Surat al-Baqarah, the verse {Whoever hastens in two days...}, from the Chapters of Interpretation. Aridat al-Ahwadhi 11/98, 99. And al-Nasa'i, in: The Chapter on the Obligation of Standing at Arafat, from the Book of Manasik of Hajj. Al-Mujtaba 5/206. And Ibn Majah, in: The Chapter on One Who Came to Arafat..., from the Book of Manasik. Sunan Ibn Majah 2/1003. And al-Darimi, in: The Chapter on What Completes the Hajj, from the Book of Manasik. Sunan al-Darimi 2/59. And Imam Ahmad, in: Al-Musnad 4/309, 310, 335. And al-Bayhaqi, in: The Chapter on One Who Catches the Hajj..., from the Book of Hajj. Al-Sunan al-Kubra 5/173. And al-Daraqutni, in: The Chapter on the Miqats (Time/Place Markers), from the Book of Hajj. Sunan al-Daraqutni 2/241.