Yithrah (יִתְרָה) denotes abundance, the excess beyond what is needed, overflow of wealth or blessing. The root is yathar (H3498, to remain over, to be left over), from which comes yether (H3499, remainder, rest, excellence). It captures the idea of surplus — more than enough.
God's economy is one of yithrah — surplus, not scarcity. The feeding of five thousand with twelve baskets leftover (perisseuō in Greek) echoes this theme. Proverbs connects yithrah to wisdom: the diligent find abundance. But prophetic literature warns that excess hoarded in injustice becomes evidence against the wealthy. True yithrah flows from God's hand and is meant to flow through God's people to the poor — abundance with open hands.
The family: yether (remainder, excellency), yithron (profit, advantage), yithrah (abundance). Ecclesiastes wrestles obsessively with yithron — "What advantage does man have?" — and concludes that earthly profit is vapor. The real surplus, implied but barely stated in Ecclesiastes, lies in fearing God (12:13). The NT reframes this through perisseuō (abundant life, John 10:10) — the yithrah that comes through Christ.