Yahya related to me from Malik from Nafi that Abdullah ibn Umarused to say, "No-one should pray over a dead person unless he is inwudu."Yahya said that he heard Malik say, "I have not seenany person of knowledge disapproving of praying over either a childborn of adultery or its mother."
USC-MSA web (English) reference: Book 16, Hadith 26
Arabic reference: Book 16, Hadith 548