Therefore, behold, I will this once {l} cause them to know, I will cause them to know my hand and my might; and they shall know that my name is JEHOVAH.

(l) They will once again feel my power and mercy for their deliverance that they may learn to worship me.

Wesley's Notes

16:21 Therefore - Because all the mercy I have shewed them, will not learn them to know my might, I will once for all make them to understand it, by the dreadful strokes of my vengeance. And - They shall know that my name is Jehovah; that I am not such a one as their idols, but one who have my being from myself, and give life and being to all other things, and have all might and power in my hand, and can do whatsoever I please.

King James Translators' Notes

The LORD: or, JEHOVAH

Scofield Reference Notes

Margin The Lord

Or, JEHOVAH. Ps 83:18.

Jamieson-Fausset-Brown Bible Commentary

21. Therefore-In order that all may be turned from idols to Jehovah, He will now give awful proof of His divine power in the judgments He will inflict.

this once-If the punishments I have heretofore inflicted have not been severe enough to teach them.

my name . Lord-Jehovah (Ps 83:18): God's incommunicable name, to apply which to idols would be blasphemy. Keeping His threats and promises (Ex 6:3).

Matthew Henry's Concise Commentary

16:14-21 The restoration from the Babylonish captivity would be remembered in place of the deliverance from Egypt; it also typified spiritual redemption, and the future deliverance of the church from antichristian oppression. But none of the sins of sinners can be hidden from God, or shall be overlooked by him. He will find out and raise up instruments of his wrath, that shall destroy the Jews, by fraud like fishers, by force like hunters. The prophet, rejoicing at the hope of mercy to come, addressed the Lord as his strength and refuge. The deliverance out of captivity shall be a figure of the great salvation to be wrought by the Messiah. The nations have often known the power of Jehovah in his wrath; but they shall know him as the strength of his people, and their refuge in time of trouble.