The Hebrew verb yasaph means to add, increase, continue, or do again. It occurs over 210 times in the Old Testament and is used to express the idea of adding more, repeating an action, or continuing in a course of behavior. It frequently appears as an auxiliary verb meaning "to do something again" or "to do something more."
Yasaph appears in contexts of both blessing and warning. God promises to add blessing upon blessing to the faithful, while also warning not to add to or subtract from His commands (Deuteronomy 4:2). The name Joseph (Yoseph) derives from this root, as Rachel said "May the LORD add to me another son" (Genesis 30:24). The word reveals God's generous, overflowing nature — He does not merely give enough, but adds abundantly beyond what is expected.