Whom did the Messenger command to learn the language of the Jews, and how did he learn it?

The Messenger of Allah, may Allah bless him and grant him peace, commanded Zayd ibn Thabit to learn words from the book of the Jews, saying: "By Allah, I do not trust the Jews with my book." So Zayd learned them in less than half a month. He was among those firmly grounded in knowledge, the Mufti of Medina, and a scribe of revelation. As for how he learned them, there are no specific details.