Verses 1-28
Psalm 102 The changeless God
Jerusalem is in ruins, God's people are in captivity, and a weary sufferer pours out his complaint to God (see heading to the psalm; also v. 13-17). The opening part of the prayer describes the psalmist's afflictions in a style similar to that of many psalms in the early part of the book. The writer is ill and dying, partly because he is unable to eat (1-5). He is lonely and cannot sleep (6-7). He is persecuted by his enemies and feels he has been deserted by God (8-11).
But how could God desert him? God is still Lord; he does not change (12). He is always faithful to his people. For example, he sees their love for their broken-down city, he hears their prayers, and he will rebuild their city for them. Israel will triumph over its enemies as of old (13-17). All who are oppressed and discouraged should take note of this and praise God. He will hear the cries of his captive people, release them from bondage and bring them back to their beloved Jerusalem (18-22).
There is no need to doubt God. Life is full of troubles and uncertainties (23-24), and even the natural world suffers from wear and tear (25-26), but God is changeless. His troubled people, from one generation to the next, can depend on him to rescue them and bless them (27-28).