ישעיהו ח:יד פירוש: רש״י ואבן עזרא

And it shall be for a portent That plan that Shebna plotted and that Pekah plotted to overthrow the kingdom of the House of David, shall be an omen [a preparationmss.] of the disaster destined to befall them.

והיה And he—namely, the King of Assyria—shall be.

for a portent Heb. לְמִקְדָשׁ, comp. (Num. 12:18) “Prepare yourself (הִתְקַדְּשׁוּ) for the morrow.”