Here's something you'd hear only on the hardscrabble streets of Philadelphia:

"Dude, you got a knife in your back."

That's what a passer-by yelled to a Philadelphia man after a bizarre incident as he was walking along Broad Street in North Philadelphia on Tuesday night.

After receiving what he thought was a punch to the back from a stranger, the victim told police that the passer-by pointed to his back and yelled about the knife.

The victim said that while walking north on Broad Street near Somerset just before 5 p.m., he passed a man looking into a storefront window. Afterward, he said he heard someone running up to him from behind.

Before he could react, he said someone had punched him in the back, without a word. After regaining his composure, he turned and saw the man, who had been looking in the window, quietly slip away around a corner.

Shaken up, he kept walking and wasn't alerted about the knife until minutes later.

Afterward, he walked to a nearby firehouse, where he was later taken to Temple University Hospital and treated for a stab wound to the upper back. Yesterday, he remained at Temple in stable condition.

Police said the victim had tried to describe his attacker, but was too shocked to give a detailed description. *