'He said:' [building upon what you can comprehend -]: My words are not play, but they are serious. These representations are not lords. 'But your Lord' is the one who deserves your exclusive worship. 'The Lord of the heavens and the earth' means the one who manages them and takes care of their interests. 'The one who created them' means He brought them into existence and split the darkness of non-existence with them. And you and your representations are among what is in them of His creations. You witness that if you return to your minds, free from desires. 'And I am upon that' the clear matter that He is your Lord alone, so the worship of others is not permissible. 'Among the witnesses' means those who are capable of establishing the evidence for what they witness, because they have not witnessed except what is with them, like the sun, not as you did when the question forced you into misguidance.