The Messenger of Allah ﷺ forbade traveling with the Quran into enemy territory. Wazad added in another narration, "out of fear that the enemy might get hold of it."
نهي رسول الله ﷺ أن يسافر بالقرآن إلى أرض العدو. وزاد في رواية: مخافة أن يناله العدو.
Malik narrated it in jihad (7) from Nafi, from Ibn Umar, as mentioned. Bukhari also narrated it in jihad and expeditions (2990), and Muslim in leadership (1869:92), both of them through Malik, with the same wording, and the addition appears following it in a version of Muslim.