My covenant will I not break
Not the covenant at Sinai, as Aben Ezra, but the covenant of grace made with Christ, and which stands fast with him, ( Psalms 89:3 Psalms 89:28 ) , which is firm, sure, and stable, and as immovable as mountains and hills, and more so, ( 2 Samuel 23:5 ) ( Isaiah 54:10 ) or "profane" F13 it, though his people profane his statutes, ( Psalms 89:31 ) , he will not profane his covenant; though they violate his laws, he is a God keeping covenant with them, and will not break his word with them:
nor alter the thing that is gone out of my lips;
any promise of his, respecting either the temporal, spiritual, or eternal welfare of his people: or "not change" F14; as he changes not in his nature and perfections, nor in his love and affections, nor in his counsels and purposes; so neither in his covenant and promises, they are always the same, and have a certain and unchangeable accomplishment; there is a performance of whatsoever is spoken by the Lord, ( Luke 1:45 ) .
F13 (llxa al) "non prophanabo", V. L. Pagninus, Montanus, Tigurine version
F14 (hnva al) "non mutabo", Pagninus, Montanus, Tigurine version, Junius & Tremellius