9:2So travel the land for four months, and know that you cannot escape God, and that God will disgrace the disbelievers.

9:36The number of months, according to God, is twelve months—in the decree of God—since the Day He created the heavens and the earth, of which four are sacred. This is the correct religion. So do not wrong yourselves during them. And fight the polytheists collectively, as they fight you collectively, and know that God is with the righteous.