Overall meaning : Allah Almighty points out that those to whom He has previously given the Torah and the Gospel (the Jews and the Christians) recognise Muhammad, may Allah bless him and grant him peace, without a shadow of a doubt as they recognise their own children, and that those who have brought utter loss upon themselves are indeed those who disbelieve Muhammad, may Allah bless him and grant him peace, and reject his message.
No one, He further indicates, does greater wrong than those who invent lies about Him or deny His Signs and proofs, stating that the wrongdoers will never attain success.
On the Day of Judgement, when Allah gathers them all together He will reprovingly ask those who ascribe partners to Him, saying, 'Where are now your false gods that you used to claim are partners with Allah?!’ They will have no answer to this question with which they will be tested other than to swear by their Lord that they did not ascribe partners to Him or worshipped them besides Him.
Then He directs His Prophet, Muhammad, may Allah bless him and grant him peace, to contemplate how they will lie to themselves on the Day of Resurrection by claiming they have never associated partners with Allah, and how the false gods they used to claim are partners with Allah will not be there to help them or benefit them in any way.