V. 18a. And unto Enoch was born Irad.
259. What opinion to form concerning this name, I really know not, for its origin is very obscure; and yet I believe the name is not accidental but prophetic. In the book of Joshua we have a city called Ai; and this same term is used elsewhere as an appellative. Now, the proper name Ai signifies, "a heap," as a heap of fallen buildings. And if with this name you compound the verb Irad, the word thus compounded will signify increase. Although the posterity of Cain, on account of their excommunication, were at that time like a great heap of ruins, it was his prayer that they might not altogether perish, but be preserved and greatly increased by means of this son Irad. If anyone can offer a better interpretation, I will by no means despise it; for on obscure points like the present, conjecture is quite allowable.
V. 18b. And Irad begat Mehujael.
260. This name is formed from the verb mahah, which signifies "to destroy," and from jaal, "he began," or "he attempted or dared." Accordingly this name signifies that the posterity of Cain should now enter upon so mighty an increase as to dare to set itself in array against the true Church and to despise it and persecute it; so mightily should it prevail by its wealth, wisdom, glory and numbers. These, indeed, are for the most part the influences through which the true Church is always overcome by the world and the false church.
V. 18c. And Mehujael begat Methushael.
261. Meth signifies "death," and schaal means "to ask," or "to demand." Hence we have the name Saul; that is, demanded. This name indicates a spirit haughtier than any of the others. I understand it to signify that Methushael threatens that he will avenge his parents, who are dead, whom the other church—that is the true Church—has punished with excommunication and exile.
V. 18d. And Methushael begat Lamech.