Sudah Makan?

I walk to work everyday. Today, it's another usual walk at the same route.

I was entering a building entrance and when the sliding glass door opened, I saw a silhouette of a man walked beside me in quite a close distance. I looked to my left and it was a Malay guard carrying an air gun, on the way to work.

As I looked at him, he looked back and asked, "Sudah makan?"
Eh...? The sudden question came out of nowhere... huh??? I replied with a smile and walked away.

Who the hell will ask a stranger "Sudah makan?" Weird.