Is it permissible to pray in the Hijr of Ismail, and what is its virtue?

The Hijr (semi-circular wall) is part of the Kaaba, and praying within it is like praying inside the Kaaba. Nafl (supererogatory) prayers are permissible within it, as the Prophet, peace and blessings be upon him, did, and as indicated by his saying to Aisha: "Pray in the Hijr if you wish to enter the House, for it is but a piece of the House." As for obligatory prayers, it is safer not to perform them in the Hijr or inside the Kaaba, because the Prophet, peace and blessings be upon him, did not do so, and because some scholars have stated their invalidity therein. The prescribed action is to perform obligatory prayers outside the Kaaba and the Hijr.