Commentators explain that the 'prayer of faith' is not a magical formula but a deep trust in God's will, offered alongside practical means (symbolized by oil, likely as medicine). The promise to 'save the sick' refers to physical recovery. However, scholars note this is not an absolute guarantee for every case, as healing is ultimately subject to God's wisdom. The goal is to encourage hopeful prayer, not to create a false expectation that believers will never die from illness.