Esias 1:20

20 but if ye be not willing, nor hearken to me, a sword shall devour you: for the mouth of the Lord has spoken this.

Esias 1:20 In-Context

18 And come, let us reason together, saith the Lord: and though your sins be as purple, I will make them white as snow; and though they be as scarlet, I will make white as wool.
19 And if ye be willing, and hearken to me, ye shall eat the good of the land:
20 but if ye be not willing, nor hearken to me, a sword shall devour you: for the mouth of the Lord has spoken this.
21 How has the faithful city Sion, full of judgment, become a harlot! wherein righteousness lodged, but now murderers.
22 Your silver is worthless, thy wine merchants mix the wine with water.

The Brenton translation of the Septuagint is in the public domain.