To be in a lowly position — geographically, socially, or spiritually. God exalts the humble and brings low the proud (1 Sam 2:7). The 'low valleys' filled and 'rough places' made level in Isaiah 40 use this root.
The exalt/humble dynamic is central to biblical theology. Mary's Magnificat (Luke 1:52) echoes Hannah's song: God has brought down the mighty and exalted those of humble estate — shaphel reversed.
Isaiah 40:3-4's preparation for God's coming involves shaphel-ing the mountains and lifting the valleys — moral and cosmic leveling for the arrival of the King. John the Baptist is this voice in the wilderness (John 1:23).