Yaval (יָבַל) appears both as a verb (to lead, conduct, bring) and as a noun meaning a stream or watercourse. The root connects the act of leading to the image of flowing water — both involve directed movement from one place to another. As a verb, it appears in prophetic contexts of triumphant procession; as a noun, in wisdom's comparison of the righteous to a tree planted by streams.
Isaiah uses the verb yaval for the eschatological procession of nations bringing gifts to Jerusalem: 'They shall bring gold and frankincense, and shall bring good news, the praises of the LORD' (Isaiah 60:6). Jeremiah 17:8 uses the noun form (yubal): the man who trusts in the LORD is like a tree planted by water that 'sends out its roots by the stream (yubal)' — a near-parallel to Psalm 1:3. The Jubilee year (yovel) shares a related root, evoking the ram's horn trumpet that called all people to freedom and restoration.
The image of being 'led' appears throughout Scripture as a picture of divine guidance. God led Israel through the wilderness like a shepherd leads a flock. Christ, the Good Shepherd, 'leads his own sheep out' (John 10:3-4). The eschatological procession — nations streaming to Zion, gifts being brought to the King — fulfills what yaval anticipates. The stream imagery connects to eternal life: 'The Lamb... will be their shepherd and will guide them to springs of living water' (Revelation 7:17).