The fifth visitation is the earthquake (Deuteronomy 29:23). I have overthrown. This is the word used to describe the destruction of Sodom and Gomorrah (Genesis 19:25; Jeremiah 20:16), and it seems better to refer the occurrence mentioned to some such convulsions of nature which caused widespread destruction, than, as Keil and others, "to the utter confusion of the state by which Israel was brought to the verge of ruin."
We do not know anything about the particular earthquake to which the prophet alludes. (For an exhaustive catalogue of the earthquakes in this country, see Pusey's notes on this verse.) As God overthrew.
The substitution of the name of God for the personal pronoun, when the Lord himself is speaking, is not uncommon in Hebrew. Here it rather takes the form of a quotation from Genesis. Ye were as a firebrand plucked out of the burning (Zechariah 3:2, where see note)—a phrase which implies, not only a narrow escape, but an escape accompanied with loss.
The "brand" not wholly consumed is yet blackened and diminished by the burning.