Surah 47

Surah 47:1

"Those who disbelieve and keep (people) from the way of God – He will lead their deeds astray."

After a series of sūras in which the messenger is merely a warner (e.g., 46.9), the tone and content of Sūra 47 strike a stunning contrast. Here the messenger must be obeyed, and his commands have to do with fighting. In addition to the judgment of Allah on the Day of Resurrection, “believers” are to punish “unbelievers” in the present life.
Among the “believers,” however, are some who do not respond to the messenger’s words in acceptable ways. To these the sūra promises various punishments and the curse of Allah.

- from The Quran with Christian Commentary: A Guide to Understanding the Scripture of Islam