The heart failing represents being terrified and losing confidence. Alternate translation: "Do not let anyone be terrified" or "Do not let anyone lose their confidence" (See: [[rc://en/ta/man/translate/figs-metonymy]])
David spoke of himself as "your servant" to show respect to Saul. Alternate translation: "I, your servant, will go" (See: [[rc://en/ta/man/translate/figs-123person]])