Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrated that he asked Sayyiduna Bilal (may Allah be pleased with him): Where did the Prophet (peace and blessings be upon him) pray inside the Ka'bah? Sayyiduna Bilal (may Allah be pleased with him) showed him where he (peace and blessings be upon him) had prayed, and he did not ask how many rak'ahs he prayed. Whenever Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) entered the House, he would walk straight ahead, leaving the door behind him, and keep walking until there remained about three cubits between him and the wall; then he would pray, seeking out the very place where Sayyiduna Bilal (may Allah be pleased with him) had told him that he (peace and blessings be upon him) had prayed.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9720