Thy light: it is put in general for all happiness and prosperity; as all kind of adversity and calamity is set forth and resembled by darkness: but here more particularly for a comfortable and free estate after their dark and calamitous condition in the Babylonish captivity; for the like reason Josephus tells us, lib. 12. cap. 11., that the Jews instituted a feast to be observed by their posterity, upon the account of the service of the temple being re-established, which they called the feast of lights, because, saith he, so great a happiness broke forth upon them beyond their hope. Break forth as the morning: here is a metaphorical allusion in a metonymical expression, viz. of the efficient, describing the comfortable effect of humbling themselves in a right manner, which like the daylight shall break forth from the blackness of their night of affliction, and bring with it the joy and comfort of all good things; and he doth not only say this light shall appear, but break forth, dart itself forth, notwithstanding all difficulties, as the sun breaks and pierceth through a cloud, noting how ready God is to help is people when they are rightly humbled, how quickly and how clearly salvation shall break forth upon them. Thine health shall spring forth speedily: another metaphor to express the same thing, unless there may be this difference, the light with reference to their outward state, and health with reference to the inward delight of their minds, in both to describe the complete satisfaction they should have. Deliverances out of great pressures are often in Scripture represented by the recovery of health, as Isaiah 57:18 Jeremiah 8:22; and this prophet especially delights in this metaphor, because all affliction is as it were a sickness to the soul, altering the heart and countenance; see Nehemiah 2:2,3; and a recovery out of this estate maketh the heart glad, and the countenance cheerful, Esther 8:16,17 Jer 33:6: compare Isaiah 58:10,11. Hence the LXX. render it; medicines. Thy righteousness; either,
1. Thy uprightness and sincerity, Genesis 30:33. Or,
2. The reward of thy righteousness, by a metonymy, Isaiah 48:18 Psalms 24:5; and here perhaps it may particularly relate to their works of mercy and charity, it being the thing in hand, and often so called, Psalms 112:9, and applied by the apostle to this purpose, 2 Corinthians 9:9. It brings temporal, spiritual, and eternal blessings, and all this not of desert, but free grace, as a reward that naturally springs forth from the faithfulness of his promises, as the harvest from the earth, when the seed is sown; see Hosea 10:12; so the fruit and reward of our righteousness springs not from our deserts, but from God's righteousness, Heb 6 10. Or,
3. The witness of thy righteousness; by what thou doest thou wilt appear to be righteous, Psalms 37:6. For such a notion as this was vulgarly sucked in, that adversity did never befall a person or people but for their sins, and was strongly urged by way of argument against Job's integrity by his friends; therefore they being delivered shall be as a testimony of thy righteousness. Or,
4. The fruit and effect of thy righteousness, viz. the due, just, and right order of thy government, which, as Calvin saith, is a sign of God's fatherly kindness; things that are now in a confusion he will bring into right order again, i.e. justice shall be duly administered, and men shall carry themselves justly all the land over: see Isaiah 32:16-18. Or,
5. Christ's righteousness, Jeremiah 23:6, compared with Isaiah 33:16. Then the meaning is, He shall go in and out before thee. Shall go before thee; as it were making way for thy better state, as the break of day or the morning star goes before the sun. The glory of the Lord, i.e. the glory of his power and providence, or his glorious power, shall be seen in bringing thee up from captivity, and defending thee free from their pursuit; or, as some, a glorious stale shall succeed this thy calamitous condition, and called the glory of the Lord to express the greatness of this glory, as very great mountains are called the mountains of God, and tall cedars the cedars of God. The glorious Lord, by a metonymy of the adjunct. Shall be thy rereward, Heb. shall gather thee: thus the word is used concerning Dan, who was appointed to bring up the rear, or to. close up the march of the Israelites, when they marched through the wilderness of Sinai, Numbers 10:25. This office God takes upon himself; for it argues great skill and courage, and makes much for the honour and glory of a commander, both to gather up all the stragglers, that none be picked up by the enemy, which relates to the Hebrew word of gathering, and to secure and cover the rear of his army; thus the angel of his presence secured the Israelites when they came up out of Egypt, Exodus 14:19.