The writer compares people with no understanding to horses and mules. Possible meanings are 1) the writer is speaking Yahweh's words to his readers, "You all must not be like a horse ... no understanding" or 2) Yahweh is speaking to the writer as though to a group of people. (See: [[rc://en/ta/man/translate/figs-simile]])
Yahweh being faithful to a person and protecting that person is spoken of as if Yahweh's covenant faithfulness surrounded the person. The abstract noun "faithfulness" can be translated as an adjective. AT: "Because Yahweh is faithful to his covenant, he will protect the one who trusts in him" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-abstractnouns]])