Ja'far bin Abdullah (may Allah have mercy on him) said: (a) I saw Muhammad bin Abbad bin Ja'far kiss the Black Stone and prostrate on it, then he said: "I saw your maternal uncle Ibn Abbas (may Allah be pleased with him) kissing it and prostrating on it."
(b) And Ibn Abbas (may Allah be pleased with him) said: I saw Umar bin al-Khattab (may Allah be pleased with him) kiss it and prostrate on it, and he said: "I saw the Messenger of Allah (peace and blessings be upon him) do this, so I did it."
(c) The wording of the Musnad of Abu Dawud al-Tayalisi is: Then Umar (may Allah be pleased with him) said: "Had I not seen the Prophet (peace and blessings be upon him) kissing you, I would not have kissed you."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9223
Abu Ja'far (may Allah have mercy on him) said: I saw Sayyiduna Ibn Abbas (may Allah be pleased with him) come on the Day of Tarwiyah. He kissed the Corner, then prostrated on it, then kissed it, then prostrated on it, three times.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9224
Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: I saw the Prophet (peace and blessings be upon him) prostrating on the Black Stone.
Sulayman (al-Tabarani) said: No one narrated it from Sufyan except Ibn Yaman; and Ibn Abi Husayn is Abdullah bin Abd al-Rahman bin Abi Husayn.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9225