The writer states the same idea both negatively and positively to emphasize that he will certainly live. (See: [[rc://en/ta/man/translate/figs-doublet]])
The writer speaks of death as if it were a person under whose power Yahweh could place the writer. AT: "he has not allowed me to die" or "he has not allowed my enemies to kill me" (See: [[rc://en/ta/man/translate/figs-personification]] and [[rc://en/ta/man/translate/figs-idiom]])