Musannaf Ibn Abi Shaybah 38621 — the first to do a thing, and who did

Sayyiduna Ibn Umar (may Allah be pleased with them both) said: The Messenger of Allah (peace and blessings be upon him), Sayyiduna al-Fadl, Sayyiduna Usamah bin Zayd and Sayyiduna Talhah bin Uthman (may Allah be pleased with them) entered the Ka'bah. Sayyiduna Ibn Umar (may Allah be pleased with them both) said: I too entered it, and the first person I met was Sayyiduna Bilal (may Allah be pleased with him), so I asked him: "Where did the Messenger of Allah (peace and blessings be upon him) pray?" He said: "Between these two pillars."