The hadith of Ibn ʿAbbās is a gharīb hadith from this chain of transmission.

54 – Chapter: What is said when the deceased is placed in the grave

1067 – Abū Saʿīd al-Ashajj narrated to us, he said: Abū Khālid al-Aḥmar narrated to us, he said: al-Ḥajjāj narrated to us, from Nāfiʿ,
from Ibn ʿUmar: that the Prophet, peace and blessings be upon him, when the deceased was placed in the grave, said – and Abū Khālid said once: when the deceased was laid in his niche (laḥd) – he said once: "In the name of God, and by God, and upon the religion of the Messenger of God." And he said once: "In the name of God, and by God, and upon the Sunnah of the Messenger of God, peace and blessings be upon him."(1)

This hadith is ḥasan gharīb from this chain of transmission.

This hadith has also been narrated from other chains of transmission, from Ibn ʿUmar, from the Prophet, peace and blessings be upon him.

And Abū al-Ṣiddīq al-Nājī narrated it from Ibn ʿUmar, from the Prophet, peace and blessings be upon him.

It has also been narrated from Abū al-Ṣiddīq al-Nājī, from Ibn ʿUmar, as a mawqūf (stopped at Ibn ʿUmar) narration as well.

55 – Chapter: What is said about a single garment being placed beneath the deceased in the grave

1068 – Zayd ibn Akhzam al-Ṭāʾī al-Baṣrī narrated to us, he said: ʿUthmān ibn--------------------------------------------
(1) A ṣaḥīḥ hadith. It was also recorded by Abū Dāwūd (3213), Ibn Mājah (1550), and it is in al-Musnad (4812), and Ṣaḥīḥ Ibn Ḥibbān (3110).