Keep his covenant ... for a thousand generations

These two phrases share similar meanings and are used together for emphasis. Here "word" refers to the covenant. AT: "Keep his covenant in mind forever, the promise that he made for a thousand generations" (See: rc://en/ta/man/translate/figs-parallelism and rc://en/ta/man/translate/figs-metonymy)

Keep his covenant in mind

This means to remember and think about his covenant. AT: "Remember his covenant" (See: rc://en/ta/man/translate/figs-idiom)

The phrase "calls to mind" means to remember something. AT: "He remembers" (See: rc://en/ta/man/translate/figs-idiom)

Both "the covenant" and "the oath" refer to the same promise that Yahweh made to his people. (See: rc://en/ta/man/translate/figs-parallelism)

This refers to the oath that he had previously made to Issac. AT: "his oath that he made to Isaac" (See: rc://en/ta/man/translate/figs-ellipsis)

"as your part"