Sanctify unto me all the firstborn, whatsoever openeth the womb among the children of Israel, both of man and of beast: it is mine.
Sanctify to me all the first-born — The parents were not to look upon themselves as interested in their first-born, till they had first solemnly presented them to God, and received them back from him again.
It is mine — By a special right, being by my singular favour preserved from the common destruction.
 And it shall be when the LORD shall bring thee into the land of the Canaanites, and the Hittites, and the Amorites, and the Hivites, and the Jebusites, which he sware unto thy fathers to give thee, a land flowing with milk and honey, that thou shalt keep this service in this month.
When the lord shall bring you into the land, thou shalt keep this service — 'Till then they were not obliged to keep the passover, without a particular command from God.
 Unleavened bread shall be eaten seven days; and there shall no leavened bread be seen with thee, neither shall there be leaven seen with thee in all thy quarters.
There shall no leavened bread be seen in all thy quarters — Accordingly the Jews usage was, before the feast of the passover, to cast all the leavened bread out of their houses; either they burnt it, or buried it, or broke it small, and threw it into the wind; they searched diligently with lighted candles in all the corners of their houses, lest any leaven should remain. The strictness enjoined in this matter was designed, 1. To make the feast the more solemn, and consequently the more taken notice of by the children, who would ask, why is so much ado made? 2. To teach us how solicitous we should be to put away from us all sin.
 And it shall be for a sign unto thee upon thine hand, and for a memorial between thine eyes, that the LORD's law may be in thy mouth: for with a strong hand hath the LORD brought thee out of Egypt.
Upon thy hand, between thine eyes — Proverbial expressions; denoting things which are never out of our thoughts.
 And every firstling of an ass thou shalt redeem with a lamb; and if thou wilt not redeem it, then thou shalt break his neck: and all the firstborn of man among thy children shalt thou redeem.
Thou shalt redeem — The price of the redemption was fixed by the law.
 And it shall be for a token upon thine hand, and for frontlets between thine eyes: for by strength of hand the LORD brought us forth out of Egypt.
For frontlets between thine eyes — As conspicuous as any thing fixt to thy forehead, or between thine eyes.
 But God led the people about, through the way of the wilderness of the Red sea: and the children of Israel went up harnessed out of the land of Egypt.
There were many reasons why God led them through the way of the wilderness of the red sea. The Egyptians were to be drowned in the Red-sea, the Israelites were to be humbled, and proved in the wilderness. Deuteronomy 32:11, teaching them by degrees to fly.
They went up harnessed — They went up by five in a rank, so some; in five squadrons, so others. They marched like an army with banners, which added much to strength and honour.
 And the LORD went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; to go by day and night:
And the Lord went before them in a pillar — In the two first stages, it was enough that God directed Moses whither to march; he knew the country, and the road; but now they are come to the edge of the wilderness, they would have occasion for a guide, and a very good guide they had, infinitely wise, kind, and faithful, the Lord went up before them; The Shechinah or appearance of the divine Majesty, which was a precious manifestation of the eternal Word, who in the fulness of time was to be made flesh, and dwell among us. Christ was with the church in the wilderness, 1 Corinthians 10:9. What a satisfaction to Moses and the pious Israelites, to be sure that they were under a divine conduct? They need not fear missing their way who were thus led, nor being lost who were thus directed; they need not fear being benighted, who were thus illuminated, nor being robbed, who were thus protected. And they who make the glory of God their end, and the word of God their rule, the spirit of God the guide of their affections, and the providence of God the guide of their affairs, may be confident that the Lord goes before them, as truly is he went before Israel in the wilderness, though not so sensibly. They had sensible effects of God's going before them in this pillar. For, It led them the way in that vast howling wilderness, in which there was no road, no track, no way-marks through which they had no guides. When they marched, this pillar went before them, at the rate that they could follow, and appointed the place of their encampment, as infinite Wisdom saw fit; which eased them from care, and secured them from danger, both in moving, and in resting. It sheltered them from the heat by day, which at sometimes of the year was extreme: And it gave them light by night when they had occasion for it.
 He took not away the pillar of the cloud by day, nor the pillar of fire by night, from before the people.
He took not away the pillar of the cloud, - No not when they seemed to have less occasion for it: it never left them 'till it brought them to the borders of Canaan. It was a cloud which the wind could not scatter. There was something spiritual in this pillar of cloud and fire. 1. The children of Israel were baptized unto Moses in this cloud, 1 Corinthians 10:2. By coming under this cloud they signified their putting themselves under the conduct and command of Moses. Protection draws allegiance; this cloud was the badge of God's protection, and so became the bond of their allegiance. Thus they were initiated, and admitted under that government, now when they were entering upon the wilderness. 2. And it signifies the special conduct and protection which the church of Christ is under in this world.