For three things the earth trembles, under four it cannot bear up:
All Commentaries on Proverbs 30:21 Go To Proverbs 30
Hippolytus of Rome
AD 235
The shaking (of the earth) signifies the change of things upon earth.—Sin, then, which in its own nature is a slave, has reigned in the mortal body of men: once, indeed, at the time of the flood; and again in the time of the Sodomites, who, not satisfied with what the land yielded, offered violence to strangers; and a third time in the case of hateful Egypt, which, though it obtained in Joseph a man who distributed food to all, that they might not perish of famine, yet did not take well with his prosperity, but persecuted the children of Israel. “The handmaid casting out her mistress:” i.e., the Church of the Gentiles, which, though itself a slave and a stranger to the promises, cast out the free-born and lordly synagogue, and became the wife and bride of Christ. By Father, Son, and Holy Spirit, the whole earth is moved. The “fourth it cannot bear:” for He came first by lawgivers, and secondly by prophets, and thirdly by the Gospel, manifesting Himself openly; and in the fourth instance He shall come as the Judge of the living and the dead, whose glory the whole creation will not be able to endure.
