Ibn Umar (may Allah be pleased with them both) was informed of this statement of Sayyidah Aishah (may Allah be pleased with her): that part of the low wall (al-Hijr) is included in the House of Allah. So Ibn Umar (may Allah be pleased with them both) said: By Allah! I think that if Aishah (may Allah be pleased with her) heard this from the Prophet (peace and blessings be upon him), then the Messenger of Allah (peace and blessings be upon him) left touching those two (corners) only because they are not on the foundations of the House of Allah, and it is for this very reason that the people performed tawaf from behind this low wall.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9314