IN THE LIGHT OF THE ABSOLUTE alternatives set out at the end of Isaiah 50---either fear the Lord and obey his Servant and know his blessing, or light your own fire and lie down in torment---Isaiah 51:1-11 opens with words of encouragement to the faithful remnant. The passage climaxes with a grand vision of returning to the Lord, of entering Zion with singing (Isa. 51:11). The words evoke the pilgrimages the godly undertook when they were in the land. In the best of circumstances these were joyful occasions, full of singing, full of personal and family memories, full of joyous expectation as the people of God wended their way to Zion, to the temple of the living God. But the pilgrimage that the prophet has in mind eclipses any other. The old pilgrimages occurred three times a year for the prescribed feasts. Here the language of pilgrimage is retained, but we are given a glimpse of the End: "They will enter Zion with singing; everlasting joy will crown their heads. Gladness and joy will overtake them, and sorrow and sighing will flee away" (Isa. 51:11). We have returned to the ultimate hope expressed in Isaiah 2:1-5 and Isaiah 11:1-16.
But the people are not there yet. If they are discouraged by their small numbers and reduced circumstances, they should remember their origins, the rock from which they were cut: Abraham started off as one man, but God "blessed him and made him many" (Isa. 51:2). So here: "The LORD will surely comfort Zion and will look with compassion on all her ruins" (Isa. 51:3). Indeed, God's salvation will last forever, and his righteousness will never fail (Isa. 51:6). Meanwhile, God's people must listen to him. They have God's "law" in their hearts (Isa. 51:7): the word properly means "instruction," and may here include not only the Law of Moses but all the instruction of God mediated through prophets and priests alike. If this word is what anchors you, the next injunction is manageable: "Do not fear the reproach of men or be terrified by their insults" (Isa. 51:7). On the long haul, they will perish like a moth-eaten garment, while God's righteousness and salvation "will last forever ... through all generations" (Isa. 51:8).
Some manuscripts preserve (probably rightly) a slightly different reading in verse 4. Instead of "my people" and "my nation," read "peoples" and "nations." That means that Isaiah 51:4-6 addresses another group of pilgrims, in addition to the Israelites---all those drawn in from around the world. All of these, together with the remnant of Israelites, constitute "the ransomed of the LORD" (Isa. 51:11; cf. Rev. 5:9-10).