isaiah 40:2 Speak ye comfortably to Jerusalem, and cry unto her, that her warfare is accomplished, that her iniquity is pardoned: for she hath received of the LORD'S hand double for all her sins. - Free Bible Online

      2. comfortably--literally, "to the heart"; not merely to the intellect.
      Jerusalem--Jerusalem though then in ruins, regarded by God as about to be rebuilt; her people are chiefly meant, but the city is personified.
      cry--publicly and emphatically as a herald cries aloud (Isa 40:3).
      warfare--or, the appointed time of her misery (Job 7:1, Margin; Job 14:14; Da 10:1). The ulterior and Messianic reference probably is the definite time when the legal economy of burdensome rites is at an end (Ga 4:3, 4).
      pardoned--The Hebrew expresses that her iniquity is so expiated that God now delights in restoring her.
      double for all her sins--This can only, in a very restricted sense, hold good of Judah's restoration after the first captivity. For how can it be said her "warfare was accomplished," when as yet the galling yoke of Antiochus and also of Rome was before them? The "double for her sins" must refer to the twofold captivity, the Assyrian and the Roman; at the coming close of this latter dispersion, and then only, can her "iniquity" be said to be "pardoned," or fully expiated [HOUBIGANT]. It does not mean double as much as she deserved, but ample punishment in her twofold captivity. Messiah is the antitypical Israel (compare Mt 2:15, with Ho 11:1). He indeed has "received" of sufferings amply more than enough to expiate "for our sins" (Ro 5:15, 17). Otherwise (cry unto her) "that she shall receive (blessings) of the Lord's hand double to the punishment of all her sins" (so "sin" is used, Zec 14:19, Margin) [LOWTH]. The English Version is simpler.

JFB.