Musannaf Ibn Abi Shayba 6:890

Hushaym narrated to us, from ‘Imran ibn Abi ‘Ata, the freed slave of Banu Asad, who said: I witnessed the death of Ibn ‘Abbas. Muhammad ibn al-Hanafiyyah took charge of his affairs. He said: He performed four takbirs over him, and he was entered [into the grave] from the direction of the Qiblah.