Judgment also will I lay to the line - The sense of this is, I will judge them according to the exact rule of law, as an architect frames everything according to the rule which he uses. In other words, there shall be no mercy intermingled. The line is used by a carpenter for measuring; the plummet consists of a piece of lead attached to a string, and is also used by carpenters to obtain a perpendicular line. A carpenter works exactly according to the lines which are thus indicated, or his frame would not be properly adjusted. So God says that he would judge the people of Jerusalem according to the exact rule, without any intermingling of mercy.
And the hail ... - (see the note at Isaiah 28:2). Hail, hailstones, and floods of waters are frequent images of the divine vengeance and wrath Psalms 105:32; Isaiah 22:19; Isaiah 30:30; Ezekiel 13:13; Ezekiel 38:22; Revelation 8:7; Revelation 11:19; Revelation 16:21.