O you who believe! be not like those who disbelieve and say of their brethren when they travel in the earth or engage in fighting: Had they been with us, they would not have died and they would not have been slain; so Allah makes this to be an intense regret in their hearts; and Allah gives life and causes death and Allah sees what you do.

And that He might know the hypocrites; and it was said to them: Come, fight in Allah's way, or defend yourselves. They said: If we knew fighting, we would certainly have followed you. They were on that day much nearer to unbelief than to belief. They say with their mouths what is not in their hearts, and Allah best knows what they conceal.

Therefore, for their breaking their covenant and their disbelief in the communications of Allah and their killing the prophets wrongfully and their saying: Our hearts are covered; nay! Allah set a seal upon them owing to their unbelief, so they shall not believe except a few.