Asalamu Alaikum Qur’an Weekly,
We’re on the 10th juz now, and this is Surah al-Tawbah and ayah number 41. This is a call of Allah to the Muslims who were actually heading out for the battle of Tabūk. This is after Mecca was conquered and Islam had become a dominant force in Arabia and there was a threat of attack from the Roman Empire.
That the Prophet (salallahu alayhi wasalaam) basically issued what you can call a military draft of all the Muslims to be ready for battle because the Roman armies were going to be one hundred thousand strong or even thirty thousand to one hundred thousand strong and the Muslims, whatever resources they had had to be put into defending Islam and moving forward and meeting the enemy.
Source: Nouman Ali Khan, Quran Weekly Channel