Hadith 503670
Chapter 9: Shortening the Prayer - كتاب قصر الصلاة فى السفر
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ عَطَاءِ بْنِ يَسَارٍ، أَنَّ كَعْبَ الأَحْبَارِ، قَالَ لَوْ يَعْلَمُ الْمَارُّ بَيْنَ يَدَىِ الْمُصَلِّي مَاذَا عَلَيْهِ لَكَانَ أَنْ يُخْسَفَ بِهِ خَيْرًا لَهُ مِنْ أَنْ يَمُرَّ بَيْنَ يَدَيْهِ .
Yahya related to me from Malik from Zayd ibn Aslam from Ata ibn Yasar that Kab al-Ahbar said, "If the person who passed in front of a man praying knew what he was bringing on himself, it would be better for him to sink into the ground than to pass in front of him."
Reference Muwatta Malik 503670
USC-MSA web (English) reference : Book 9, Hadith 38