The church is called so, and said to be terrible. (Song of Solomon 6:10) And in allusion to the same, the Lord himself is called the Lord of hosts. And hence, that expression in the hymn, Holy, holy, holy, Lord God of Sabaoth, or rather Zebaoth, which signifies, hosts or armies. Beautifully the Lord takes this title to himself; not only to indicate the greatness of his power, but the greatness of his security to his church and people, in his care and government over them. And it is a blessed thing to have this Lord God of Zebaoth for our stay.
See Sabaoth