Sunan Ibn Majah, Hadith 946 ⓘ
It was narrated that Abu Hurairah said: “The Prophet said: ‘If anyone of you knew (how great is the sin involved) in passing in front of his brother while he is performing prayer, waiting for one hundred years would be better for him than one step that he takes.’”
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا وَكِيعٌ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ مَوْهَبٍ، عَنْ عَمِّهِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ النَّبِيُّ ـ صلى الله عليه وسلم ـ " لَوْ يَعْلَمُ أَحَدُكُمْ مَا لَهُ فِي أَنْ يَمُرَّ بَيْنَ يَدَىْ أَخِيهِ مُعْتَرِضًا فِي الصَّلاَةِ كَانَ لأَنْ يُقِيمَ مِائَةَ عَامٍ خَيْرٌ لَهُ مِنَ الْخَطْوَةِ الَّتِي خَطَاهَا " .
also referenced under: Book 5, Hadith 999 (In-Book) & Volume 2, Book 5, Hadith 946 (DarusSalam)