Arabic (Original)
حَدَّثَنَا عُمَرُ بْنُ هَارُونَ عَنْ ثَوْرِ بْنِ يَزِيدَ عَنْ شُرَيْحٍ عَنْ جُبَيْرِ بْنِ نُفَيْرٍ الْحَضْرَمِيِّ عَنْ نَوَّاسِ بْنِ سَمْعَانَ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَبُرَتْ خِيَانَةً تُحَدِّثُ أَخَاكَ حَدِيثًا هُوَ لَكَ مُصَدِّقٌ وَأَنْتَ بِهِ كَاذِبٌ.
English Translation
Umar ibn Harun narrated to us, from Thawr ibn Yazid, from Shurayh, from Jubayr ibn Nufayr al-Hadrami, from Nawwas ibn Sam'an, who said: The Messenger of Allah, peace and blessings be upon him, said: 'It is a grave betrayal that you tell your brother something and he believes you to be truthful about it, while you are lying to him.'