how to find file defining an alias

I am having a problem I'm not sure how to get around.

Somehwhere on my system, I have an alias defined as such:

alias subl=\''/Applications/Sublime Text http://2.app/Contents/SharedSupport/bin/subl'\'

I am not sure what file this is in, and I want to change (or actually remove) it.

I could just unalias it in my .zshrc, but that's not as elegant a solution.

When I run alias | grep subl it shows me the alias. Is there a way for me to have it also echo the path to the file defining the alias?

Thanks