A Servant and A Dumb Person (Surah An-Nahl 16:75-76)

75. Allah gives the example of a servant under the possession of another, he has no power of any sort, and a man on whom We have bestowed good provisions from Us, and he spends from that secretly and openly. Can they be equal (By no means). All the praises and thanks are to Allah. Nay! (But) most of them know not.

76. And Allah gives an example of two men, one of them dumb, who has no power over anything, and he is a burden on his master; whichever way he directs him, he brings no good. Is such a man equal to one who commands justice, and is himself on the straight path.

The Example of the Believer and the Disbeliever, or the Idol and the True God

Al-`Awfi reported that Ibn `Abbas said: "This is the example which Allah gives of the disbeliever and the believer.'' This was also the view of Qatadah and Ibn Jarir. The servant who has no power over anything is like the disbeliever, and the one who is given good provisions and spends of them secretly and openly is like the believer. Ibn Abi Najih reported that Mujahid said: "This is an example given of the idol and the True God - can they be the same'' Once the difference between them is so clear and so obvious, no one can be unaware of it except the one who is foolish. Allah says:

All the praises and thanks are to Allah. Nay! (But) most of them know not.

Another Example

Mujahid said, "This also refers to idols and the True God, may He be exalted.'' Meaning that the idol is dumb and cannot speak or say anything, good or otherwise. It cannot do anything at all, no words, no action, it is dependent and is a burden on its master.

whichever way he directs him,  meaning, wherever he sends him

he brings no good meaning, he does not succeed in what he wants.

Is such a man equal meaning, a man who has these attributes

to one who commands justice  meaning fairness, one whose words are true and whose deeds are righteous.

and is himself on the straight path Al-`Awfi reported that Ibn `Abbas said: "This is also an example of the disbeliever and the believer'', as in the previous Ayah.

Reference: Tafsir ibn Kathir (abridged) English version.