At what instant - literally, "in a moment." Here, "at one time - at another time."

At what instant I shall speak concerning a nation, etc. - If that nation, against whom, etc. - And at what instant, etc. - If it do evil, etc. - These verses contain what may be called God's decree by which the whole of his conduct towards man is regulated. If he purpose destruction against an offending person, if that person repent and turn to God, he shall live and not die. If he purpose peace and salvation to him that walketh uprightly, if he turn from God to the world and sin, he shall die and not live.

At what instant I shall speak concerning a nation, and concerning a kingdom,.... By way of threatening: or, "the moment I shall speak" (s), &c; as soon as ever I have declared concerning any people whatever, Jews or Gentiles; that if they go on in their sins, and remain impenitent, and do not turn from them, that they must expect I will quickly come out against such a nation and kingdom in a providential way, as threatened:

to pluck up, and to pull down, and to destroy it; as the proprietor of a garden, when it do not turn to his account, plucks up the plants, and pulls down the fences, and lets it go to ruin.

(s) "momento loquor", Schmidt; "momento eloquor", Junius & Tremellius; "momento ut loquutus fuero", Tigurine version.

At what instant I shall speak concerning a nation, and concerning a kingdom, to pluck up, and to pull down, and to destroy it;

7. At what instant-in a moment, when the nation least expects it. Hereby he reminds the Jews how marvellously God had delivered them from their original degradation, that is, In one and the same day ye were the most wretched, and then the most favored of all people [Calvin].

18:1-10 While Jeremiah looks upon the potter's work, God darts into his mind two great truths. God has authority, and power, to form and fashion kingdoms and nations as he pleases. He may dispose of us as he thinks fit; and it would be as absurd for us to dispute this, as for the clay to quarrel with the potter. But he always goes by fixed rules of justice and goodness. When God is coming against us in judgments, we may be sure it is for our sins; but sincere conversion from the evil of sin will prevent the evil of punishment, as to persons, and to families, and nations.