isaiah 42:4 He shall not fail nor be discouraged, till he have set judgment in the earth: and the isles shall wait for his law. - Free Bible Online

      4. fail--faint; man in religion may become as the almost expiring flax-wick (Isa 42:3), but not so He in His purposes of grace.
      discouraged--literally, "broken," that is, checked in zeal by discouragements (compare Isa 49:4, 5). ROSENMULLER not so well translates, "He shall not be too slow on the one hand, nor run too hastily on the other."
      judgment--His true religion, the canon of His judgments and righteous reign.
      isles . . . wait, &c.--The distant lands beyond sea shall put their trust in His gospel way of salvation. Mt 12:21 virtually gives the sense, with the inspired addition of another aspect of the same thing, "In his name shall the Gentiles trust" (as "wait for" here means, Isa 30:18). "His law" is not something distinct from Himself, but is indeed Himself, the manifestation of God's character ("name") in Christ, who is the embodiment of the law (Isa 42:21; Jer 23:6; Ro 10:4). "Isles" here, and in Isa 42:12, may refer to the fact that the populations of which the Church was primarily formed were Gentiles of the countries bordering on the Mediterranean.

JFB.