'Lord of Hosts' in the Bible

And the said man went out of his city every feastful day, to pray and to offer unto the LORD of Hosts: where the two sons of Eli - Hophni and Phinehas - were the LORD's priests.

and vowed a vow and said, "LORD of Hosts, if thou wilt look on the wretchedness of thine handmaid and shalt remember me and not forget thine handmaid, and shalt give unto thine handmaid a man child I will give him unto the LORD all the days of his life and there shall neither razor or shears come upon his head."

And the people sent to Shiloh, and fetched from thence the ark of the covenant of the LORD of Hosts which dwelleth between the Cherubims. And there were the two sons of Eli, Hophni and Phinehas with the ark of the covenant of God.

Thus sayeth the LORD of Hosts: 'I have called to remembrance that which Amalek did to Israel; how they lay in wait for them in the way, as they came out of Egypt.

Then said David to the Philistine, "Thou comest to me with a sword, a spear, and a shield: But I come to thee in the name of the LORD of Hosts, the God of the host of Israel whom thou hast railed upon.