Charles Ellicott Commentary Psalms 78:38

"But he, being merciful, forgave [their] iniquity, and destroyed [them] not: Yea, many a time turned he his anger away, And did not stir up all his wrath." — Psalms 78:38 (ASV)

The verbs in the first clause should be in the present, But he, the compassionate, forgives iniquity, and does not destroy, and many a time he turned away, and so on.