Narrated Zayd ibn Thabit:

The Messenger of Allah ﷺ ordered me (to learn the writing of the Jews), so I learnt for him the writing of the Jews. He said: I swear by Allah, I do not trust Jews in respect of writing for me. So I learnt it, and only a fortnight passed before I mastered it. I would write for him when he wrote (to them), and read to him when something was written to him.

حَدَّثَنَا أَحْمَدُ بْنُ يُونُسَ، حَدَّثَنَا ابْنُ أَبِي الزِّنَادِ، عَنْ أَبِيهِ، عَنْ خَارِجَةَ، - يَعْنِي ابْنَ زَيْدِ بْنِ ثَابِتٍ - قَالَ قَالَ زَيْدُ بْنُ ثَابِتٍ أَمَرَنِي رَسُولُ اللَّهِ ﷺ فَتَعَلَّمْتُ لَهُ كِتَابَ يَهُودَ وَقَالَ " إِنِّي وَاللَّهِ مَا آمَنُ يَهُودَ عَلَى كِتَابِي " . فَتَعَلَّمْتُهُ فَلَمْ يَمُرَّ بِي إِلاَّ نِصْفُ شَهْرٍ حَتَّى حَذَقْتُهُ فَكُنْتُ أَكْتُبُ لَهُ إِذَا كَتَبَ وَأَقْرَأُ لَهُ إِذَا كُتِبَ إِلَيْهِ .