Sunan Ibn Majah, Book 5, Hadith 998 (In-Book) ⓘ

It was narrated from Busr bin Sa’eed that Zaid bin Khalid sent word to Abu Juhaim Al-Ansari asking him: “What did you hear from the Prophet about a man when he is performing prayer?” He said: “I heard the Prophet saying: ‘If anyone of you knew (how great is the sin involved) when he passed in front of his brother who is performing prayer, then waiting for forty’,” (one of the narrators) said: “I do not know if he meant forty years, forty months, or forty days, ‘would be better for him than that.”

حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا سُفْيَانُ، عَنْ سَالِمٍ أَبِي النَّضْرِ، عَنْ بُسْرِ بْنِ سَعِيدٍ، أَنَّ زَيْدَ بْنَ خَالِدٍ، أَرْسَلَ إِلَى أَبِي جُهَيْمٍ الأَنْصَارِيِّ يَسْأَلُهُ مَا سَمِعْتَ مِنَ النَّبِيِّ، ـ صلى الله عليه وسلم ـ فِي الرَّجُلِ يَمُرُّ بَيْنَ يَدَىِ الرَّجُلِ وَهُوَ يُصَلِّي فَقَالَ سَمِعْتُ النَّبِيَّ ـ صلى الله عليه وسلم ـ يَقُولُ ‏ "‏ لَوْ يَعْلَمُ أَحَدُكُمْ مَالَهُ أَنْ يَمُرَّ بَيْنَ يَدَىْ أَخِيهِ وَهُوَ يُصَلِّي كَانَ لأَنْ يَقِفَ أَرْبَعِينَ - قَالَ لاَ أَدْرِي أَرْبَعِينَ عَامًا أَوْ أَرْبَعِينَ شَهْرًا أَوْ أَرْبَعِينَ يَوْمًا - خَيْرٌ لَهُ مِنْ ذَلِكَ ‏" ‏ ‏.‏