Isaiah 1:20

New English Translation

²⁰But if you refuse and rebel,
you will be devoured^[a] by the sword.”
Know for certain that the Lord has spoken.^[b]

Isaiah 1:20 sn The wordplay in the Hebrew draws attention to the options. The people can obey, in which case they will “eat” v. 19 (תֹּאכֵלוּ [toʾkhelu], Qal active participle of אָכַל) God’s blessing, or they can disobey, in which case they will be devoured (Heb “eaten,” תְּאֻכְּלוּ, [t^eʾukk^elu], Qal passive/Pual of אָכַל) by God’s judgment.
Isaiah 1:20 tn Heb “for the mouth of the Lord has spoken.” The introductory כִּי (ki) may be asseverative (as reflected in the translation) or causal/explanatory, explaining why the option chosen by the people will become reality (it is guaranteed by the divine word).

New English Translation (NET)