I believed, therefore have I spoken: I was greatly afflicted:
I believed, therefore have I spoken. As the former strophe was occupied with the deliverance, so this is taken up with the thanksgiving for it. "I believed," as Abraham did (Genesis 15:6; Psalms 27:13); not that the Psalmist boasts of his faith, but mentions it in order to glorify the Lord, who had given him according to his faith. "Therefore have I spoken" (2 Corinthians 4:13). What he spake is not expressed, but implied in Psalms 116:11. While distrusting "men," he doubtless spake out his hearty trust in God. Confession with the mouth must attest the belief of the heart; otherwise one's faith is very dubious (Romans 10:9-10).
I was greatly afflicted. It was affliction that called his faith and confession into exercise.