I used to write everything which I heard from the Messenger of Allah ﷺ. I intended (by it) to memorise it. The Quraysh prohibited me saying: Do you write everything that you hear from him while the Messenger of Allah ﷺ is a human being: he speaks in anger and pleasure? So I stopped writing, and mentioned it to the Messenger of Allah ﷺ. He signalled with his finger to him mouth and said: Write, by Him in Whose hand my soul lies, only right comes out from it.
كُنْتُ أَكْتُبُ كُلَّ شَىْءٍ أَسْمَعُهُ مِنْ رَسُولِ اللَّهِ ﷺ أُرِيدُ حِفْظَهُ فَنَهَتْنِي قُرَيْشٌ وَقَالُوا أَتَكْتُبُ كُلَّ شَىْءٍ تَسْمَعُهُ وَرَسُولُ اللَّهِ ﷺ بَشَرٌ يَتَكَلَّمُ فِي الْغَضَبِ وَالرِّضَا فَأَمْسَكْتُ عَنِ الْكِتَابِ فَذَكَرْتُ ذَلِكَ لِرَسُولِ اللَّهِ ﷺ فَأَوْمَأَ بِأُصْبُعِهِ إِلَى فِيهِ فَقَالَ اكْتُبْ فَوَالَّذِي نَفْسِي بِيَدِهِ مَا يَخْرُجُ مِنْهُ إِلاَّ حَقٌّ