And I will bring a sword upon you,.... War upon them by the sword of their enemies; they that use and kill with the sword, as the Targums of Onkelos and Jonathan; their neighbours that delighted in war, and bore an implacable, hatred unto them, and gladly embraced every opportunity of shedding their blood, and ravaging their country:

that shall avenge the quarrel of my covenant; the covenant made with them at Sinai, which they transgressed, and for which vengeance would be taken on them in this way, God so ordering it in his providence, though the enemy meant it not, Isaiah 10:5,

and when ye are gathered together within your cities; from the fields and villages, fleeing from the enemy invading and destroying, to their fortified towns and cities for safety:

I will send the pestilence among you; which shall destroy those that escaped the sword, and thought themselves safe in a strong city, and even the very soldiers in the garrisons, who were set for the defence of the city:

and ye shall be delivered into the hand of the enemy; so many being taken off by the pestilence, there would not be a sufficient number to defend the place, and therefore obliged to give it up, by which means those that escaped the pestilence would fall into the hands of the enemy.

He would bring over them "the sword avenging (i.e., executing) the covenant vengeance." The "covenant vengeance" was punishment inflicted for a breach of the covenant, the severity of which corresponded to the greatness of the covenant blessings forfeited by a faithless apostasy. If they retreated to their towns (fortified places) from the sword of the enemy, the Lord would send a plague over them there, and give those who were spared by the plague into the power of the foe. He would also "break in pieces the staff of bread," and compel them by the force of famine to submit to the foe. The means of sustenance should become so scarce, that ten women could bake their bread in a single oven, whereas in ordinary times every woman would require an oven for herself; and they would have to eat the bread which they brought home by weight, i.e., not as much as every one pleased, but in rations weighed out so scantily, that those who ate would not be satisfied, and would only be able to sustain their life in the most miserable way. Calamities such as these burst upon Israel and Judah more than once when their fortified towns were besieged, particularly in the later times of the kings, e.g., upon Samaria in the reign of Joram (2 Kings 6:25.), and upon Jerusalem through the invasions of the Chaldeans (cf. Isaiah 3:1; Jeremiah 14:18; Ezekiel 4:16; Ezekiel 5:12).

And I will bring a sword upon you, that shall avenge the quarrel of my covenant: and when ye are gathered together within your cities, I will send the pestilence among you; and ye shall be delivered into the hand of the enemy.

26:25 The quarrel of my covenant - That is, my quarrel with you for your breach of your covenant made with me.

26:14-39 After God has set the blessing before them which would make them a happy people if they would be obedient, he here sets the curse before them, the evils which would make them miserable, if they were disobedient. Two things would bring ruin. 1. A contempt of God's commandments. They that reject the precept, will come at last to renounce the covenant. 2. A contempt of his corrections. If they will not learn obedience by the things they suffer, God himself would be against them; and this is the root and cause of all their misery. And also, The whole creation would be at war with them. All God's sore judgments would be sent against them. The threatenings here are very particular, they were prophecies, and He that foresaw all their rebellions, knew they would prove so. TEMPORAL judgments are threatened. Those who will not be parted from their sins by the commands of God, shall be parted from them by judgments. Those wedded to their lusts, will have enough of them. SPIRITUAL judgments are threatened, which should seize the mind. They should find no acceptance with God. A guilty conscience would be their continual terror. It is righteous with God to leave those to despair of pardon, who presume to sin; and it is owing to free grace, if we are not left to pine away in the iniquity we were born in, and have lived in.