This is an order from Allah (swt) to the Messenger Muhammad (saws). He announces to the jinn his Message clearly, that is he worships Allah (swt) alone, and this is the Message of monotheism. Nothing should be worshipped besides Allah (swt), be it idols, humans, stars or animals, for Allah (swt) is the only One God. Some scholars said that this verse is a response to the disbelievers of Mecca when they asked the Prophet (saws) to renounce his call and they will in return protect him, so that the Prophet (saws) answer them by the saying of Allah (swt): (Say, “I only invoke my Lord and do not associate with Him anyone.”).