The writer speaks of gray hair as if it were a crown. "Gray hair" is a metonym for old age. AT: "A person who has lived long enough to have gray hair is like one who wears a glorious crown on his head" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-metonymy]])
# it is gained
This can be stated in active form. AT: "a person gains it" (See: [[rc://en/ta/man/translate/figs-activepassive]])