It is narrated from Makhul (may Allah have mercy on him): In this mosque I stood beside Sayyiduna Anas (may Allah be pleased with him) and asked him about performing ablution after funerals. He said: Earlier we were in prayer, and now we have returned to prayer (the funeral prayer), (so) there is no ablution.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1471