The Hebrew mibchar comes from bachar (to choose/select) and means "choice things" or "the best of something." It describes what is most desirable and excellent — the cream of a flock, the finest warriors, the choicest goods. The word appears in contexts of warfare (Exodus 15:4), divine appointment (Isaiah 22:7), and offerings.
Mibchar (choice/best) reflects the biblical principle that God deserves and receives the finest. In Exodus 15:4, Pharaoh's mibchar officers drowned in the Red Sea — God defeated Egypt's best. In offerings, Israel was commanded to bring the firstfruits, the mibchar of crops and flocks. The principle extends to service: giving God our best effort, our choicest time, our finest devotion — not the leftovers. Malachi rebukes those who offered blind and lame animals, holding back the mibchar for themselves.