The Prophet ﷺ came to the grave of Abdullah bin Ubayy after he had been buried. He had him brought out, blew some of his saliva onto him, and clothed him in his own shirt.In another narration, he placed him on his knees.
أتى النبي ﷺ قبر عبد الله بن أبي بعد ما دفن، فأخرجه فنفث فيه من ريقه، وألبسه قميصه. وفي رواية: فوضعه على ركبتيه.
Bukhari related it in the Book of Funerals (1270), and Muslim in the Book of the Qualities of the Hypocrites (2773), both from the hadith of Sufyan bin Uyayna, from Amr (he is Ibn Dinar), who heard Jabir bin Abdullah say, then he mentioned it.His statement, "after he had been buried," means he had been lowered into his grave. The family of Abdullah bin Abu had been concerned about placing a burden on the Prophet ﷺ by requiring his presence, so they hurried to prepare him for burial before the Prophet ﷺ arrived. When he arrived, he found that they had already lowered him into his grave, so he ordered that he be taken out, in fulfillment of his promise to shroud him in his shirt and to pray over him. This is as stated in Fath al-Bari (3/139).