Ibn Umar narrated that the Prophet said: “Enjoy this House (i.e. The Ka'bah) because it was demolished twice before, and will be lifted after it gets demolished the third time.” [Ibn Hibbaan and Al-Haakim: Authentic according to the conditions of Al-Bukhari and Muslim]
In another narration, Ibn Umar narrated: “I heard the Prophet saying: ‘He who circumambulates the House and then prays two Rak'ahs will get the reward of the one who frees a slave.’” [Ibn Maajah: Al-Albaani-Authentic]
'Ali said, “Circumambulate the House as much as you can before you are prevented; a time will come when a bald headed man with small ears will rise on it and demolish it with his shovel.” ['Abdurrazzaaq] Another narration reads, “Circumambulate the House as much as you can before you are prevented; a time will come when an Ethiopian bald headed man with small ears and thin legs will sit on its ruins as it is being demolished it with his shovel.” ['Abu 'Ubaydah]
The abovementioned narrations prove and indicate that the Ka'bah will get demolished by a thin legged Ethiopian man. Abu Hurayrah narrated that the Prophet said: “The Ka'bah will be demolished by the thin legged Ethiopian man.” [Al-Bukhari and Muslim]
Muslim scholars said that it is recommended for the one who visits the House (Ka'bah) to circumambulate it as much as he/she can. As a matter of fact, some of the scholars are of the opinion that circumambulating the House (Ka'bah) is more rewarding than offering optional prayers in the Ka'bah.
Ibn Taymiyyah said: “Tawaaf (circumambulating the Ka'bah) is the act worship done the most during Hajj. A pilgrim is instructed to perform it upon arriving and before departing, in addition to the types that are pillars of Hajj, such as Al-Ifaadhah which is performed after one leaves Arafah and then Muzdalifah. It is recommended for one to perform it during the days he stays in Mina. In general, it is recommended all year round.”
In another statement, Ibn Taymiyyah said: “It is better for a person to circumambulate the Ka'bah than to walk purposelessly.”
From the above texts, it becomes evident that, for the one who visits Makkah for Hajj or 'Umrah or simply visiting, circumambulating the Ka'bah is one of the best acts of worship by which he/she draws close to Allah The Almighty. However, the one who offers optional Tawaaf (circumambulation) should avoid, as much as possible, circumambulating the Ka'bah during the times of congestion when the House is overcrowded, such as the day of 'Eed and the three days that follow, lest one disturbs others.