Kharijah bin Zayd narrates from his father that when the Prophet (peace and blessings be upon him) came to Madinah, I was brought to him. I recited something before him (peace and blessings be upon him), and he (peace and blessings be upon him) said to me: "Learn the script of the Jews, for I do not trust their scribes." Sayyiduna Zayd (may Allah be pleased with him) said: Fifteen days had not passed before I learned it. Then I used to write for the Prophet (peace and blessings be upon him), and it was I who would read their letters out to the Prophet (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12195