Make no mention of the name of other gods. There is no sort of doubt but that this declaration should be connected with the Third Commandment. Moses explains that God's name is taken in vain and abused, if men swear by other gods; for it is not lawful to refer the judgment of things unknown to any other than the one true God. Consequently, the glory of the Deity is transferred to those by whose name men swear. Therefore by the Prophet God pronounces a severe denunciation, that He will destroy all those that swear by His name, and also by Malcham, (Zephaniah 1:5,) since thus the Jews mixed Him up with their idol, and so profaned His holiness. In sum, since by swearing we profess that He is our God, whom we declare to be both the knower of our hearts and the judge of our souls, the true God justly claims this honor for Himself alone, inasmuch as the glory of His name is detracted from, not only if we speak less reverently than we should of Him, but also if we associate with Him such as may usurp a part of His rights. And this more clearly appears from the two passages which we have adduced from Deuteronomy, wherein the people are commanded to swear by the name of the one God, which is equivalent to rendering to His sacred name in our outward profession of service the unmixed reverence which it deserves. [1] Still God does not exhort the people to indulge themselves freely in oaths, as if by frequent oaths they exercised themselves in the duties of piety, but simply means that when there is occasion for it or necessity, and a just cause shall demand it, they must swear in no other way than by invoking Him alone as their witness and judge.

Footnotes

1 - "Ce qui vaut autant comme de luy rendre l'hommage qu'il merite, en le constituant tesmoin des choses cachees, et confessant que c'est a luy seul de maintenir la verite;" which is equivalent to rendering to Him the homage He deserves, in constituting Him the witness of hidden things, and confessing that it is His alone to maintain the truth. -- Fr.

Compare Deuteronomy 4:9; Joshua 22:5; Ephesians 5:15.

And in all [things] that I have said unto you be circumspect: and make (f) no mention of the name of other gods, neither let it be heard out of thy mouth.
(f) Neither by swearing by them, nor speaking of them, (Psalm 16:4; Ephesians 5:3).

And in all things that I have said unto you, be circumspect,.... Or observe them, be careful to keep them punctually and constantly, even all that are delivered in this and the preceding chapters:
and make no mention of the name of other gods; neither call upon them, nor swear by them, nor make vows to them; and, as little as possible, ever utter their names, and never with pleasure and delight, and showing any honour of them, and reverence to them, but with the utmost detestation and abhorrence:
neither let it be heard out of thy mouth; not any of their names; the same thing in different words, the more to inculcate and impress the thing upon the mind, and to show with what vehemence and earnestness this is pressed.

make no mention of the name of other gods, &c.--that is, in common conversation, for a familiar use of them would tend to lessen horror of idolatry.

In all things that I have said unto you be circumspect - We are in danger of missing our way on the right hand and on the left, and it is at our peril if we do, therefore we have need to look about us. A man may ruin himself through mere carelessness, but he cannot save himself without great care and circumspection; particularly since idolatry was a sin they were much addicted to, and would be greatly tempted to, they must endeavour to blot out the remembrance of the gods of the heathen, and must disuse all their superstitious forms of speech, and never mention them but with detestation. In Christian schools and academies (for it is in vain to think of re - forming the play - houses) it were to be wished that the names and stories of the heathen deities or demons rather were not so commonly and familiarly used.