I put the city on my back
So that way if I fall
I'm crowd surfing the map

from Big Sean – Intro Lyrics on Rap Genius

Meaning

He reps Detroit heavily, so even with that weight on his back, if he falls, his city would show him love right back and he would crowd surf on the support of their hands

To help improve the meaning of these lyrics, visit “Intro” by Big Sean Lyrics and leave a comment on the lyrics box