Sa'id bin Ubayd (may Allah have mercy on him) delivered a sermon and said: If we are martyred tomorrow, do not wash us, do not remove our clothes, and do not shroud us except in the very clothes that are on us.
We have already narrated in the Book of Funerals that Sayyiduna Ali (may Allah be pleased with him) offered the funeral prayer over Sayyiduna Ammar bin Yasir and Sayyiduna Hashim bin Utbah (may Allah be pleased with them both).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16773