The verb of multiplication and abundance. God's first commands involve rabah: 'Be fruitful and multiply' (Gen 1:28). The fulfillment of covenant blessing is measured by increase.
Used of population growth, animal reproduction, and the increase of wisdom or sin. The Abrahamic promise of descendants 'as numerous as stars' uses this root's imagery throughout Genesis.
The multiplication command (Gen 1:28) is a commission — humanity as image-bearers filling and governing creation. Covenant blessing is often quantified as increase: more children, more land, more years.