Then went Boaz up to the gate - We have often had occasion to remark that the gate or entrance to any city or town was the place where the court of justice was ordinarily kept. For an account of the officers in such places, see the note on Deuteronomy 16:18.
Ho, such a one! - sit down here - This familiar mode of compellation is first used here. The original is אלמני פלני פה שבה shebah poh, peloni almoni ! "Hark ye, Mr. Such-a-one of such a place! come and sit down here." This is used when the person of the individual is known, and his name and residence unknown. אלמני almoni comes from אלם alam, to be silent or hidden, hence the Septuagint render it by κρυφε thou unknown person: פלני peloni comes from פלה palah, to sever or distinguish; you of such a particular place. Modes of compellation of this kind are common in all languages.