This is a superscription that tells about the psalm. Some scholars say that this is part of the scripture and some say that it is not. (See "What are Superscriptions in Psalms" in [Introduction to Psalms](../front/intro.md).)
These phrases have similar meanings. They can be stated in active form. Alternate translation: "who God forgives his transgression and covers his sin" (See: [[rc://en/ta/man/jit/figs-parallelism]] and [[rc://en/ta/man/jit/figs-activepassive]])
Here sin that is forgiven is spoken of as if it were covered so that it can not be seen. Alternate translation: "whose sin is ignored" or "whose sin is deliberately forgotten" (See: [[rc://en/ta/man/jit/figs-metaphor]])