The "first-born of the poor" signifies the most miserable of the poor (Isa 14:30). The "church of the first-born" signifies the church of the redeemed.
Menephtah is probably the Pharaoh whose first-born was slain. His son did not succeed or survive his father, but died early. The son's tomb has been found at Thebes unfinished, showing it was needed earlier than was expected. Some of the records on the tomb are as follows: "The son whom Menephtah loves; who draws towards him his father's heart, the singer, the prince of archers, who governed Egypt on behalf of his father. Dead."
FIRST-BORN. The first-born, who was the object of special affection to his parents, was denominated by way of eminence, ??? ???, the opening of the womb. In case a man married with a widow, who by a previous marriage had become the mother of children, the first-born as respected the second husband was the eldest child by the second marriage. Before the time of Moses, the father might, if he chose, transfer the right of primogeniture to a younger child, but the practice occasioned much contention, Ge 25:31-32; and a law was enacted, overruling it, De 21:15-17. The first-born inherited peculiar rights and privileges.
(1.) He received a double portion of the estate. Jacob, in the case of Reuben, his first-born, bestowed his additional portion upon Joseph, by adopting his two sons, Ge 48:5-8; De 21:17. This was done as a reprimand, and a punishment of his incestuous conduct, Ge 35:22; but Reuben, notwithstanding, was enrolled as the first- born in the genealogical registers, 1Ch 5:1.
(2.) The first-born was the priest of the whole family. The honour of exercising the priesthood was transferred, by the command of God communicated through Moses, from the tribe of Reuben, to whom it belonged by right of primogeniture, to that of Levi, Nu 3:12-18; 8:18. In consequence of God having taken the Levites from among the children of Israel instead of all the first-born to serve him as priests, the first-born of the other tribes were to be redeemed, at a valuation made by the priest not exceeding five shekels, from serving God in that capacity, Nu 18:15-16; Lu 2:22, &c.
(3.) The first-born enjoyed an authority over those that were younger, similar to that possessed by a father, Ge 25:23, &c; 2Ch 21:3; Ge 27:29: Ex 12:29: which was transferred in the case of Reuben by Jacob their father to Judah, Ge 49:8-10. The tribe of Judah, accordingly, even before it gave kings to the Hebrews, was every where distinguished from the other tribes. In consequence of the authority which was thus attached to the first-born, he was also made the successor in the kingdom. There was an exception to this rule in the case of Solomon, who, though a younger brother, was made his successor by David at the special appointment of God. It is very easy to see in view of these facts, how the word "first-born" came to express sometimes a great, and sometimes the highest, dignity.
2. First-born is not always to be understood literally; it is sometimes taken for the prime, most excellent, most distinguished of any thing. "The first- born of the poor," Isa 14:30, signifies the most miserable of the poor; and "the first-born of death," Job 18:13, the most terrible of deaths.
3. God ordained that all the Jewish first-born, both of men and beasts, for service, should be consecrated to him. The male children only were subject to this law. If a woman's first child were a girl, the father was not obliged to offer any thing for her, or for the children after her, though they were males. If a man had many wives, he was obliged to offer the first-born of each of them to the Lord. The first-born were offered in the temple, and were redeemed for the sum of five shekels. The firstling of a clean beast was offered at the temple, not to be redeemed, but to be killed. An unclean beast, a horse, an ass, or a camel, was either redeemed or exchanged. An ass was redeemed by a lamb, or five shekels; if not redeemed, it was killed.