COMMENTARY on 12:40
Mustafa Khattab:

Translation:
Whatever ˹idols˺ you worship instead of Him are mere names which you and your forefathers have made up13—a practice Allah has never authorized. It is only Allah Who decides. He has commanded that you worship none but Him. That is the upright faith, but most people do not know.
Commentary:
13   Meaning, “You call them gods while in fact they are not gods.”

 

A. Yusuf Ali:

Translation:
"If not Him, you worship nothing but names which you have named,- 1693 you and your fathers,- for which Allah have sent down no authority: the command is for none but Allah. He have commanded that you worship none but Him: that is the right religion, but most men understand not...
Commentary:

1693  'If you name other gods, they are nothing but your inventions—names which you and your fathers put forward without any reality behind them. Who gave you authority to do any such thing? The only reality is Allah. Authority can come from Him alone. It is only for Him to command. And He has distinctly commanded you to worship none other than Him. That is the only religion that is right—that has stood and will stand and endure forever. He has revealed it at all times by His Messengers and by His Signs. If men fail to understand, It is their own fault (Cf. 7:71, 13:33, and 53:23).

 

Muhammad Asad:

Translation:
"All that you worship instead of God is nothing but [empty] names which you have invented 42 - you and your forefathers- [and] for which God has bestowed no warrant from on high. Judgment [as to what is right and what is wrong] rests with God alone-[and] He has ordained that you should worship nought but Him: this is the [one] ever-true faith; but most people know it not 43
Commentary:
42  Lit., "names which you have named" -i.e., "figments of your own imagination".
43  Cf. the last sentence of 30:30.