Work quote from Leonardo da Vinci

Heard this quote in church today. I believe it comes from the Aaronic Priesthood manual:

"God sells us all things at the price of labor." -Leonardo da Vinci

How profound is that quote! Think about who Leonardo da Vinci was -- one of the greatest inventors in history and one of the most intelligent people to walk this earth. And yet, as can be inferred from this quote, he wasn't prideful about his accomplishments. In fact, da Vinci recognized that we can receive any blessing from God, but God expects us to work for it.

I believe this fits well with Jeffrey R. Holland's observation that "salvation is not a cheap experience." If "it was never, ever easy" for Christ, can we expect to not do anything and become joint-heirs with Christ? Paul explained to the Romans:

"The Spirit itself beareth witness with our spirit, that we are the children of God:
And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together." (Romans 8:16-17; emphasis mine)