O Lord God of hosts - Yahweh, God of armies. That is either
(a) the God who rules among the hosts of heaven - the inhabitants of that holy world; or
(b) God of the hosts of the sky - the worlds above - the stars, that seem marshalled as hosts or armies, and that are led forth each night with such order and grandeur; or
(c) God of the hosts on earth - the armies that are mustered for war. The phrase is one which is often applied to God. See the notes at Psalms 24:10; and at Isaiah 1:24.
How long wilt thou be angry - Margin, as in Hebrew, wilt thou smoke. The allusion is derived from the comparison of anger with fire. See the notes at Psalms 74:1.
Against the prayer of thy people - That is, Thou dost not answer their prayer; thou seemest to be angry against them even when they pray; or in the act of calling upon thee. The earnest inquiry here is, how long this was to continue. It seemed as if it would never end. Compare the notes at Psalms 77:7-9.