Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said that he (peace and blessings be upon him) offered the funeral prayer over a grave a month later.
Ali (al-Daraqutni) said: Bishr bin Adam is alone in narrating it, and others contradicted him in narrating it from Abu Asim.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 7004