Possible meanings are 1) "strong legs" is a metonym that represents how swiftly a man can run. AT: "men who can run swiftly" or 2) "strong legs" represents the strength of the whole man. AT: "how strong a man is" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-synecdoche]])
# who hope in his covenant faithfulness
The abstract noun "faithfulness" can be translated with and adjective. AT: "who trust him because he is faithful to his covenant" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])