Benedicite

When a priest saluted or was asked for his blessing,, he said "Benedicite," Bless ye,—*Domino*, or, in worse Latin, *nomen Dei*. understood. Can any one say why *Benedicat* or *Benedicimini* was not used, as the use of *Benedicite* was intended to convey or invoke a blessing, not an exhortation to bless.