Muwatta Malik, Book 16, Hadith 11 (USC-MSA) ⓘ
Yahya related to me from Malik that Ibn Shihab said, "Walking behind the bier is in contradiction to the sunna."
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، أَنَّهُ قَالَ الْمَشْىُ خَلْفَ الْجَنَازَةِ مِنْ خَطَإِ السُّنَّةِ .
also referenced under: Book 16, Hadith 533 (In-Book)