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 صلى الله عليه وسلم 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 ‏.‏

Narrated Zayd ibn Thabit: The Messenger of Allah (PBUH) 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. Translation Not Available

Book reference: Sunan Abi Dawud Book 26 Hadith 3645
Web reference: Sunan Abi Dawud Book 25 Hadith 3638