John Trapp on Psalms 102:13

Verſ. 13. Thou ſhalt ariſe, and have mercy upon Sion] This hee ſpeaketh with as much confidence, as if he had been in Gods boſome; for hee knew the promiſe of deliverance, after ſeventy years captivity. See the like Hab. 1.12.

For the time to favour her, &c.] This he underſtood by books, as Dan. 9.2. and therefore preſſeth God to a ſpeedy performance. God loveth to be burdened with his own word, to be ſued upon his own bond, &c. But beſides the promiſe, the Pſalmiſt had another ground of his confidence, and that is in the next.