"Indeed, those who like that immorality should spread," meaning: should become widespread, "among those who have believed will have a painful punishment in this world and the Hereafter." They are the hypocrites; they used to like that in order to slander the Prophet, peace be upon him, and to enrage him. The punishment of this world for the hypocrites is that the Zakat is taken from them, and what they spend in military expeditions is taken unwillingly.