John Gill Commentary Psalms 80:19

"Turn us again, O Jehovah God of hosts; Cause thy face to shine, and we shall be saved." — Psalms 80:19 (ASV)

Turn us again, O Lord God of hosts
This is a repetition of (Psalms 80:3Psalms 80:7) , in which may be observed an increase of the names or titles of the Divine Being: in (Psalms 80:3) , it is only "O God"; in (Psalms 80:7) "O God of hosts"; and here, "Lord God of hosts"; some have thought that the doctrine of the Trinity is here suggested; which is a better thought than that of Jarchi's, who supposes that three captivities of Israel are pointed at: but as it follows,

cause thy face to shine, and we shall be saved ;
it appears that this was the burden of their song, being in darkness and distress, that they might have the light of God's countenance, and therefore repeat it again and again.