One shall say, I am the LORD'S; and another {e} shall call himself by the name of Jacob; and another shall write with his hand to the LORD, and surname himself by the name of Israel.

(e) By this diversity of speech he means one thing, that is, that the people will be holy, and receive the true religion from God, as in Ps 87:5.

Wesley's Notes

44:5 Israel - The blessing of God upon the Jews shall be so remarkable, that the Gentiles shall join them, and accept the Lord for their God.

Jamieson-Fausset-Brown Bible Commentary

5. The third clause answers in parallelism to the first, the fourth to the second.

I am the Lord's-(Jer 50:5; 1Co 6:19, 20; 2Co 8:5).

call himself by the name of Jacob-The Gentiles (as the result of the outpouring of the Holy Spirit on Israel, the Lord's "seed," first) shall join themselves to the children of Jacob, in order to worship their God (compare Isa 43:7; Ps 49:11). Or, "calls," that is, invokes and celebrates the name of Jacob, attaches himself to his nation and religion [Maurer], (Ps 24:6).

subscribe . hand unto . Lord-in solemn and public covenant, pledging himself to God's service (compare Ne 9:38), before "witnesses" (Heb 12:1), after the manner of a civil contract (Jer 32:10, 12, 44). So the Christian in the sacraments [Barnes]. Literally, "shall fill his hand with letters (Ex 32:15; Eze 2:10) in honor of Jehovah"; or "shall write upon his hand, I am Jehovah's" (compare Isa 49:16; Re 13:16); alluding to the puncture with ink on the hand, whereby a soldier marked himself as bound to his commander; and whereby the Christians used to mark themselves with the name of Christ [Lowth]. The former view is simpler.

surname himself . Israel-Maurer and Gesenius interpret this as the Hebrew sanctions, answering to their rendering of the parallel second clause, "calls blandly (speaks in honorable terms of) the name of Israel." Retaining English Version, we must, from the Hebrew understand it thus, "Surname himself by the honorable name of Israel" (Isa 45:4).

Matthew Henry's Concise Commentary

44:1-8 Israel is here called Jeshurun, which means the upright one. Such only are Israelites indeed, in whom is no guile. Those that serve God he will own. He will help them over difficulties, and in their services. Water is the emblem of the Holy Spirit; as water refreshes, cleanses, and makes the earth fruitful, so do his influences the soul. This gift of the Holy Ghost is the great blessing, the plentiful pouring out of which God kept for the latter days. Where God gives his Spirit, he will give all other blessings. Hereby shall be a great increase of the church; thus it shall be spread to distant places. Was there any other Rock, or Protector, that could defend them? None besides could foretell these things to come, of which God by his prophets gave notice. All was set in order in the Divine predictions, as well as in the Divine purposes. Could any other have done so? Who can compare with Israel's Redeemer and King?