Biblical Commentary on the Old Testament, by Carl Friedrich Keil and Franz Delitzsh, [1857-78], at sacred-texts.com
Proclamation of the Tenth Plague; or the Decisive Blow. - Exo 11:1-3. The announcement made by Jehovah to Moses, which is recorded here, occurred before the last interview between Moses and Pharaoh (Exo 10:24-29); but it is introduced by the historian in this place, as serving to explain the confidence with which Moses answered Pharaoh (Exo 10:29). This is evident from Exo 11:4-8, where Moses is said to have foretold to the king, before leaving his presence, the last plague and all its consequences. ויּאמר therefore, in Exo 11:1, is to be taken in a pluperfect sense: "had said;" and may be grammatically accounted for from the old Semitic style of historical writing referred to in the commentary on Gen 2:18-22, as Gen 2:1 and Gen 2:2 contain the foundation for the announcement in Gen 2:4-8. So far as the facts are concerned, Gen 2:1-3 point back to Exo 3:19-22. One stroke more (נגע) would Jehovah bring upon Pharaoh and Egypt, and then the king would let the Israelites go, or rather drive them out. כּלה כּשׁלּחו, "when he lets you go altogether (כּלה adverbial as in Gen 18:21), he will even drive you away."
In this way Jehovah would overcome the resistance of Pharaoh; and even more than that, for Moses was to tell the people to ask the Egyptians for articles of silver and gold, for Jehovah would make them willing to give. The renown acquired by Moses through his miracles in Egypt would also contribute to this. (For the discussion of this subject, see Exo 3:21-22.) The communication of these instructions to the people is not expressly mentioned; but it is referred to in Exo 12:35-36, as having taken place.
Moses' address to Pharaoh forms the continuation of his brief answer in Exo 10:29. At midnight Jehovah would go out through the midst of Egypt. This midnight could not be "the one following the day on which Moses was summoned to Pharaoh after the darkness," as Baumgarten supposes; for it was not till after this conversation with the king that Moses received the divine directions as to the Passover, and they must have been communicated to the people at least four days before the feast of the Passover and their departure from Egypt (Exo 12:3). What midnight is meant, cannot be determined. So much is certain, however, that the last decisive blow did not take place in the night following the cessation of the ninth plague; but the institution of the Passover, the directions of Moses to the people respecting the things which they were to ask for from the Egyptians, and the preparations for the feast of the Passover and the exodus, all came between. The "going out" of Jehovah from His heavenly seat denotes His direct interposition in, and judicial action upon, the world of men. The last blow upon Pharaoh was to be carried out by Jehovah Himself, whereas the other plagues had been brought by Moses and Aaron. מצרים בּתוך "in (through) the midst of Egypt:" the judgment of God would pass from the centre of the kingdom, the king's throne, over the whole land. "Every first-born shall die, from the first-born of Pharaoh, that sitteth upon his throne, even unto the first-born of the maid that is behind the mill," i.e., the meanest slave (cf. Exo 12:29, where the captive in the dungeon is substituted for the maid, prisoners being often employed in this hard labour, Jdg 16:21; Isa 47:2), "and all the first-born of cattle." This stroke was to fall upon both man and beast as a punishment for Pharaoh's conduct in detaining the Israelites and their cattle; but only upon the first-born, for God did not wish to destroy the Egyptians and their cattle altogether, but simply to show them that He had the power to do this. The first-born represented the whole race, of which it was the strength and bloom (Gen 49:3). But against the whole of the people of Israel "not a dog shall point its tongue" (Exo 11:7). The dog points its tongue to growl and bite. The thought expressed in this proverb, which occurs again in Jos 10:21 and Judith 11:19, was that Israel would not suffer the slightest injury, either in the case of "man or beast." By this complete preservation, whilst Egypt was given up to death, Israel would discover that Jehovah had completed the separation between them and the Egyptians. The effect of this stroke upon the Egyptians would be "a great cry," having no parallel before or after (cf. Exo 10:14); and the consequence of this cry would be, that the servants of Pharaoh would come to Moses and entreat them to go out with all the people. "At thy feet," i.e., in thy train (vid., Deu 11:6; Jdg 8:5). With this announcement Moses departed from Pharaoh in great wrath. Moses' wrath was occasioned by the king's threat (Exo 10:28), and pointed to the wrath of Jehovah, which Pharaoh would soon experience. As the more than human patience which Moses had displayed towards Pharaoh manifested to him the long-suffering and patience of his God, in whose name and by whose authority he acted, so the wrath of the departing servant of God was to show to the hardened king, that the time of grace was at an end, and the wrath of God was about to burst upon him.
In Exo 11:9 and Exo 11:10 the account of Moses' negotiations with Pharaoh, which commenced at Exo 7:8, is brought to a close. What God predicted to His messengers immediately before sending them to Pharaoh (Exo 7:3), and to Moses before his call (Exo 4:21), had now come to pass. And this was the pledge that the still further announcement of Jehovah in Exo 7:4 and Exo 4:23, which had already been made known to the hardened king (Exo 11:4.), would be carried out. As these verses have a terminal character, the vav consecutive in ויּאמר denotes the order of thought and not of time, and the two verses are to be rendered thus: "As Jehovah had said to Moses, Pharaoh will not hearken unto you, that My wonders may be multiplied in the land of Egypt, Moses and Aaron did all these wonders before Pharaoh; and Jehovah hardened Pharaoh's heart, so that he did not let the children of Israel go out of his land."