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. (Using translation from Abū Dāʾūd 3646)
كُنْتُ أَكْتُبُ كُلَّ شَيْءٍ أَسْمَعُهُ مِنْ رَسُولِ اللهِ ﷺ أُرِيدُ حِفْظَهُ فَنَهَتْنِي قُرَيْشٌ عَنْ ذَلِكَ وَقَالُوا تَكْتُبُ وَرَسُولُ اللهِ ﷺ يَقُولُ فِي الْغَضَبِ وَالرِّضَا؟ فَأَمْسَكْتُ حَتَّى ذَكَرْتُ ذَلِكَ لِرَسُولِ اللهِ ﷺ؟ فَقَالَ اكْتُبْ فَوَالَّذِي نَفْسِي بِيَدِهِ مَا خَرَجَ مِنْهُ إِلَّا حَقٌّ