Fiqh-us-Sunnah Volume 5, Hajj and ‘Umrah, Fiqh 5.118.

There is consensus among the Muslims that Tawaf AI-lfadah is one of the essentials of Hajj, and if someone fails to observe it his Hajj is void. The Qur’an (22.29) says: “Then, let them complete the rites prescribed for them, perform their vows, and (again) circumambulate the Ancient House”. According to Ahmad a pilgrim must make a definite intention for its performance.

All the other three Imams hold that having the intention to perform Hajj covers and applies to all its rites including Tawaf Al-Ifadah.

The majority of scholars holds that Tawaf AI-lfadah is comprised of seven rounds of the Ka’bah. Abu Hanifah, however, is of the view that only four of the seven rounds are essential in Hajj, and if these (four) are missed the Hajj of a person becomes void. The remaining three rounds are necessary (wajib) but not essential. A pilgrim abandoning one or all of these three rounds misses a necessary part, but it does not invalidate his Hajj, although he is required to offer a sacrifice of an animal in atonement for it.