Romans 9:29

29 And, as Isaiah has said before, Except Yahweh of hosts had left us a seed, We had become as Sodom, and had been made like Gomorrah.[fn]

Yahweh of hosts, a title for God as in 1 Sam 17:45. Also compare other uses of the 'host(s)' designation in Deut 20:9 and 1 Sam 12:9.