Hadith 505330
Chapter 16: Burials - كتاب الجنائز
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، أَنَّهُ قَالَ الْمَشْىُ خَلْفَ الْجَنَازَةِ مِنْ خَطَإِ السُّنَّةِ .
Yahya related to me from Malik that Ibn Shihab said, "Walking behind the bier is in contradiction to the sunna."
Reference Muwatta Malik 505330
USC-MSA web (English) reference : Book 16, Hadith 11