I will not execute the fierceness of mine anger, I will not return to destroy Ephraim: for I am God, and not man; the Holy One in the midst of thee: and I will not enter into the city.
I will not return to destroy Ephraim - i:e., I will no more, as in past times, destroy Ephraim. The destruction primarily meant is probably that by Tiglath-pileser, who, as the Jewish king Ahaz's ally against Pekah of Israel and Rezin of Syria, deprived Israel of Gilead, Galilee, and Naphtali (2 Kings 15:29). The ulterior reference is to the long dispersion hereafter, to be ended by God's covenant-mercy restoring His people, thenceforth to be 'destroyed no more,' not for their merits, but of His grace.
For I am God, and not man - not dealing as man would, with implacable wrath under awful provocation (Isaiah 55:7-9: Malachi 3:6, "I am the Lord, I change not; therefore ye sons of Jacob are not consumed"). I do not, like man, change when once I have made a covenant of everlasting love, as with Israel (Numbers 23:19). We measure God by the human standard, and hence, are slow to credit fully His promises: these, however, belong to the faithful remnant, not to the obstinately impenitent.
The Holy One in the midst of thee - as peculiarly thy God (Exodus 19:5-6).
And I will not enter into the city - as an enemy: as I entered Admah, Zeboim, and Sodom, utterly destroying them; whereas I will not utterly destroy thee. Somewhat similarly Jerome: 'I am not one such as human dwellers in a city, who take cruel vengeance; I save those whom I correct.' Thus "not man," and "in the midst of thee," are parallel to "into the city." Though I am in the midst of thee, it is not as man entering a rebellious city to destroy utterly. Maurer needlessly translates х bª`iyr (H5892)], 'I will not come in wrath.'