Look, Shmoopers. Shakespeare whipped up 154 sonnets in this cycle so, naturally, he's going to have a few go-to metaphors that he's not afraid to reuse every now and again.
One of his favs pops up in Sonnet 146 when the speaker asks "Why so large cost, having so short a lease, / Dost thou upon thy fading mansion spend?" Translation: why spend so much time, effort, and money on a body ("aging mansion") that's just going to die because life is so "short"? This nifty metaphor is based on the notion that the mortal body is like a house and we all just rent our bodies for a short time. The idea is that when we die, our immortal souls leave or, move out.
It turns out that the speaker of the sonnets says something similar in Sonnet 13 when he warns his younger friend that he should hurry up and have some kids because he's just got a "lease" on his "beauty" for just a short amount of time (Sonnet 13, line 5).