in these three rhymed verses:

No one has ever declared the One to be one,
For everyone who declares Him one is a denier.

The tawhīd of one who speaks of His attributes
Is a loan that the One has invalidated.

His declaring Himself one is His tawhīd,
While the description of whoever describes Him is deviant.”

I say:

I have discussed (1) [this and its like] at length elsewhere (2). Here, however, we shall draw attention to what pertains to this context. We therefore say: The [first] tawhīd (3) that he mentioned is the tawhīd brought by the messengers and revealed in the Scriptures. It is the tawhīd for which Allah sent all the messengers, from first to last.

Allah Most High says:

“Ask those of Our messengers whom We sent before you: Did We ever appoint deities besides the Most Merciful to be worshipped?”

[Surah al-Zukhruf: 45].

And Allah Most High says:

“We certainly sent a messenger to every nation, saying, ‘Worship Allah and shun false deities.’ Among them were some whom Allah guided, while others were subject to the decree of misguidance.”

[Surah al-Nahl: 36].

And Allah Most High says:

“We never sent any messenger before you without revealing to him: ‘There is no deity except Me, so worship Me.’”

[Surah al-Anbiyā': 25].

Allah Most High has related of every messenger—such as Noah, Hūd, Sālih, Shu'ayb, and others—that they said to their people: “Worship Allah; you have no deity other than Him.” This was the first and final call of the messengers.