The meaning of “אֶחָד”

“And said, If Esau come to the one company, and smite it, then the other company which is left shall escape.”

“And Samson called unto the Lord, and said, O Lord God, remember me, I pray thee, and strengthen me, I pray thee, only this once, O God, that I may be at once avenged of the Philistines for my two eyes.”

“Go and tell David, saying, Thus saith the Lord, I offer thee three things: choose thee one of them, that I may do it unto thee.”

“God hath spoken once; twice have I heard this; that power belongeth unto God.”

“And every little chamber was one reed long, and one reed broad; and between the little chambers were five cubits; and the threshold of the gate by the porch of the gate within was one reed.”