Answer:
Step-by-step explanation:
Answer
I mean, it's not that you can't pass
ten or fifteen years inside
and more -
you can,
as long as the jewel
on the left side of your chest doesn't lose it's luster
The bolded part is the metaphor. A jewel is compared positively with a person's heart. The heart must continue to shine beautifully in spite of being imprisoned.
Inside is also at least a symbol but it is compared to being held in a prison.