Sunan Abu Dawud
2610
Sahih+3

‘Abd Allaah bin ‘Umar said “The Apostle of Allaah(ﷺ) prohibited to travel with a copy of the Qur’an to the enemy territory. The narrator Malik said “(It is) I think lest the enemy should take it

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid