Allah says:

{Say} - 'O Muhammad' -

meaning, 'if this were so, then I would worship Him on that basis, because I am one of His servants; I obey all that He commands me and I am not too arrogant or proud to worship Him.' This conditional phrase does not mean that what is described could happen nor that is possible as Allah says:

{Had Allah willed to take a son, He could have chosen whom He willed out of those whom He created. But glory be to Him! He is Allah, the One, the Irresistible.} (39:4). Allah says here:

meaning, exalted and sanctified and glorified be the Creator of all things far above having any offspring, for He is Unique, One and Eternally Self-Sufficient. There is none equal to Him or like Him, and He does not have any offspring.

{So leave them (alone) to speak nonsense} means, in their ignorance and misguidance,

{and play} in their world,

which is the Day of Resurrection, i.e., then they will come to know what their end and destination will be on that Day.

The Uniqueness of the Lord

means, He is the God of those who are in the heavens and the God of those who are on earth; all of them worship Him and are humbled before Him.

{And He is the All-Wise, the All-Knower.} This Ayah is like the Ayah:

{And He is Allah in the heavens and on the earth; He knows what you conceal and what you reveal, and He knows what you earn.} (6:3)

which means, He is the One who is called Allah in the heavens and on the earth.

means, He is their Creator and Sovereign, the One Who is controlling them with none to resist or oppose His rule. Blessed and exalted be He far above the notion of His having a child. He is eternally free of all faults and shortcomings.

means, no one knows when it will happen except Him.

means, and each person will be requited for his deeds; if they are good, then he will be rewarded, and if they are evil, then he will be punished.

means, the false gods and idols.

{of intercession} means, they will not be able to intercede for them.

This is an exception (meaning, but those who bear witness to the truth will be able to intercede). This means, those who acknowledge that there is no god except Allah, {knowingly, and they know} in their hearts the meaning of the words that their lips speak. They will be able to intercede with Allah - by His leave - for those whom He wills.

means, they will admit that He is the Creator of all things and He has no partner in that. Yet despite that they still worship others alongside Him who have nothing and are able to do nothing. This is the utmost foolishness and stupidity. Allah says:

The Prophet's Complaint to Allah

means, Muhammad said this; he complained to his Lord about his people who did not believe in him, and said, 'O Lord, these people do not believe.' This is like the Ayah:

{And the Messenger will say: "O my Lord! Verily, my people deserted this Qur'an."} (25:30).

This is the view of Ibn Mas'ud, may Allah be pleased with him, Mujahid and Qatadah, and this is how Ibn Jarir interpreted it.

Al-Bukhari said: "Abdullah - meaning Ibn Mas'ud, may Allah be pleased with him - recited (Ayah 88 of Az-Zukhruf):

(And the Messenger will say: "O my Lord!")
Mujahid said concerning the Ayah:

"Allah is stating what Muhammad said." Qatadah said, "These are the words of your Prophet, when he complained about his people to his Lord."

{So turn away from them,} means, from the idolators.

{and say Salam (peace!)} means, 'do not respond to them in the same evil manner in which they address you; but try to soften their hearts and forgive them in word and deed.'

{But they will come to know.} This is a warning from Allah for them. His punishment, which cannot be warded off, struck them, and His religion and His word was supreme. Subsequently Jihad and striving were prescribed until the people entered the religion of Allah in crowds, and Islam spread throughout the east and the west. And Allah knows best.

This is the end of the Tafsir of Surat Az-Zukhruf.