Isaiah 58:14

Then shalt thou delight thyself in the Lord: this hath reference to the foregoing verse. If thou wilt delight thyself in the sabbath, then thou shalt delight in the God of the sabbath; or thou shalt have cause to delight in the Lord, viz. in his goodness and faithfulness to thee, and so shalt live by faith in him as the Fountain of all good, as Psalms 37:4, in the assurance of his love and favour, Psalms 33:21, and that in great abundance, Psalms 36:8; such delights as no wicked man call have, Proverbs 14:10. I will cause thee to ride upon the high places of the earth; thou shalt be above the reach of danger, Isaiah 33:16. Or it may have respect to their being brought out of Babylon, which lay very low in respect of Judea, called the earth, as it is elsewhere, Luke 23:44; and high, both in respect of the situation of it, as also its mountainousness. Or the expression may import the subduing of their enemies, as it is Deuteronomy 33:29. Riding is oft used for conquering, Psalms 45:4; see the note there; Revelation 6:2. The sense is, they shall come out of Babylon, not sneakingly, as on foot, but triumphantly and gloriously, riding, as God brought Israel out of Egypt harnessed, in good order, and with a high hand; or, they shall ride to and fro in their chariots at their pleasure. And feed thee with the heritage of Jacob, i.e. thou shalt enjoy the good of the land of Canaan, which God had promised as a heritage of Jacob and his seed, Genesis 35:12, and feed on the fruits of it. Quest. Why doth he say of the heritage of Jacob, and not of Abraham or Isaac. Answ. Because the whole posterity of Jacob was within the covenant, but Ishmael and Esau, one the seed of Isaac, the other the seed of Abraham, were both excluded. For the mouth of the Lord: this is to express the certainty and indubitableness of it, being from the mouth of him who cannot lie: see of the same expression of assurance, Isaiah 1:20, Isaiah 40:5. And this Calvin refers both to what was spoken in the beginning of the chapter, that it was in vain for those hypocrites to contend with God; and also as the confirmation of his promise, if they would rightly observe those promises. The mouth of the Lord hath spoken it: he speaks of himself, as of a man, by a prosopopoeia; or it may relate to the prophet, the Lord, whose mouth and instrument I am.