Sauce is a Johnnie Walker "Game Changer" whiskey commercial:

Redditor bloodyshart give the context:

Johnnie Walker, with the permission of the Bruce Lee estate, has used CGI to "bring Bruce Lee back to life", as it were. They say that it's meant to be more of an inspirational thing and not something to just shill booze. Lee never partook in alcohol, instead being a fan of marijuana and a justified user of pain medication following a severe training accident. But alcohol never meshed with his training regimen. It destroys one's reflexes and the body's ability to recover.

Be water, my friend.

http://pandawhale.com/post/13020/be-water-my-friend-empty-your-mind-bruce-lee

http://pandawhale.com/post/6501/bruce-lee-be-water-my-friend

Empty your cup so that it may be filled. ~Bruce Lee