These phrases have similar meanings. They can be stated in active form. AT: "who God forgives his transgression and covers his sin" (See: [[rc://en/ta/man/translate/figs-parallelism]] and [[rc://en/ta/man/translate/figs-activepassive]])
Here sin that is forgiven is spoken of as if it were covered so that it can not be seen. AT: "whose sin is ignored" or "whose sin is deliberately forgotten" (See: [[rc://en/ta/man/translate/figs-metaphor]])