Whoever saw the Prophet ﷺ passing by a secluded grave, then prayed over it with his companions lined up in rows behind him.He was asked, "Who narrated this to you?"He replied, "Ibn Abbas."
أخبرنا يعقوب بن إبراهيم قال حدثنا هشيم قال الشيباني أنبأنا
من رأى النبي ﷺ مر بقبر منتبذ فصلى عليه وصف أصحابه خلفه قيل من حدثك قال ابن عباس
[Sahih] See the previous hadith. It is also found in Kubra, hadith no. 2151.