The “Lamb” is the crucified and risen Lamb mentioned in Revelation 5:6, who had taken the scroll from God’s hand. So the very one who died for sin and now controls the opening of the seals of the scroll—and therefore the events God had determined should happen in the world to gather his church—will function as their Shepherd. As a faithful Shepherd, he will “guide them to springs of living water,” in fulfillment of David's song in Psalm 23:1–2. See also Jesus’ description of himself as the Good Shepherd in John 10:1–42.
17 For the Lamb in the midst of the throne will be their shepherd, and he will guide them to springs of living water, and God will wipe away every tear from their eyes.”