I heard Kaʿb b. Malik - the transmitter Ibn al-Sarh then narrated the story of his remaining behind from the Prophet ﷺ during the campaign of Tabuk - say: The Messenger of Allah ﷺ forbade the Muslims to speak to any of us three. When (in this state) abundant time passed on me, I ascended the wall of the garden of Abu Qatadah who was my cousin. I saluted him, but, I swear by Allah, he did not return salute to me. He then narrated the story of the revelation of the Qur’anic verses relating to his repentance.  

عَنِ النَّبِيِّ ﷺ فِي غَزْوَةِ تَبُوكَ قَالَ وَنَهَى رَسُولُ اللَّهِ ﷺ الْمُسْلِمِينَ عَنْ كَلاَمِنَا أَيُّهَا الثَّلاَثَةُ حَتَّى إِذَا طَالَ عَلَىَّ تَسَوَّرْتُ جِدَارَ حَائِطِ أَبِي قَتَادَةَ وَهُوَ ابْنُ عَمِّي فَسَلَّمْتُ عَلَيْهِ فَوَاللَّهِ مَا رَدَّ عَلَىَّ السَّلاَمَ ثُمَّ سَاقَ خَبَرَ تَنْزِيلِ تَوْبَتِهِ