Who smote the Egyptians in, their first-born Some read with their first-born, but the other rendering reads better. As we do not mean to sermonize upon the passage, it is unnecessary to detain the reader here with many words, as nothing is mentioned but what has been treated elsewhere. Only we may notice that the Egyptians are well said to have been smitten in their first-born, because they continued in their outrageous obstinacy under the other plagues, though occasionally terrified by them, but were broken and subdued by this last plague, and submitted. As it was not intended to recount all the wonders successively done in Egypt, the whole is summed up in one word when it is said, that he led his people forth from the midst of it with a mighty and a stretched out arm. For pressed down as they were on every side, it was only by a wonderful display of divine power that they could effect an escape. The figure of an outstretched arm is appropriate, for we stretch out the arm when any great effort is required; so that this implies that God put forth an extraordinary and not a common or slight display of his power in redeeming his people.

To him that smote Egypt in their first-born - Exodus 12:29. That is, he struck them down, or destroyed them, by his own direct power.
For his mercy - It was in mercy to his people. It was the means of their deliverance from bondage, for the Egyptians would not otherwise have suffered them to depart. By all the results of their deliverance both to themselves and to mankind, the act was seen to be an act of mercy to the world. It was better for mankind that the Hebrews should be delivered even at this sacrifice than it would have been that they should not be brought into the promised land.

Smote Egypt in their first-born - This was one of the heaviest of strokes: a great part of the rising generation was cut off; few but old persons and children left remaining.

To him that smote Egypt in their firstborn,.... In a tender part, in the dear part of themselves, in their sons and heirs, and who were to inherit their lands and estates, and perpetuate their names; this was an act of justice for using ill the Lord's firstborn, the people of Israel, slaying their sons, and refusing to let them go, Exodus 1:13; and yet there was mercy in it, for which thanks were to be given to God;
for his mercy endureth for ever; the Israelites, in a very merciful manner, were distinguished by the blood sprinkled on their door posts, when the destroying angel passed through the land of Egypt to destroy their firstborn; and when they were destroyed, it was owing to the kind providence of God that the Egyptians did not rise as one man to cut off the Israelites in vengeance; and yet not a dog was suffered to move his tongue against them when the dismal cry was made; yea, this was the means of their deliverance, which could not be obtained by all the other plagues; but now they not only bid them go, but were urgent upon them to be gone, Exodus 11:5.

The great things God did for Israel, when he brought them out of Egypt, were mercies which endured long to them; and our redemption by Christ, which was typified thereby, endures for ever. It is good to enter into the history of God's favours, and in each to observe, and own, that his mercy endureth for ever. He put them in possession of a good land; it was a figure of the mercy of our Lord Jesus Christ.

Up to this point it is God the absolute in general, the Creator of all things, to the celebration of whose praise they are summoned; and from this point onwards the God of the history of salvation. In Psalm 136:13 גּזר (instead of בּקע, Psalm 78:13; Exodus 14:21; Nehemiah 9:11) of the dividing of the Red Sea is peculiar; גּזרים (Genesis 15:17, side by side with בּתרים) are the pieces or parts of a thing that is cut up into pieces. נער is a favourite word taken from Exodus 14:27. With reference to the name of the Egyptian ruler Pharaoh (Herodotus also, ii. 111, calls the Pharaoh of the Exodus the son of Sesostris-Rameses Miumun, not Μενόφθας, as he is properly called, but absolutely Φερῶν), vid., on Psalm 73:22. After the God to whom the praise is to be ascribed has been introduced with ל by always fresh attributes, the ל before the names of Sihon and of Og is perplexing. The words are taken over, as are the six lines of Psalm 136:17-22 in the main, from Psalm 135:10-12, with only a slight alteration in the expression. In Psalm 136:23 the continued influence of the construction הודוּ ל is at an end. The connection by means of שׁ (cf. Psalm 135:8, Psalm 135:10) therefore has reference to the preceding "for His goodness endureth for ever." The language here has the stamp of the latest period. It is true זכר with Lamed of the object is used even in the earliest Hebrew, but שׁפל is only authenticated by Ecclesiastes 10:6, and פּרק, to break loose = to rescue (the customary Aramaic word for redemption), by Lamentations 5:8, just as in the closing verse, which recurs to the beginning, "God of heaven" is a name for God belonging to the latest literature, Nehemiah 1:4; Nehemiah 2:4. In Psalm 136:23 the praise changes suddenly to that which has been experienced very recently. The attribute in Psalm 136:25 (cf. Psalm 147:9; Psalm 145:15) leads one to look back to a time in which famine befell them together with slavery.