Employing or being employed without a tlush

Employing or being employed without a tlush

I Went for a job interview at a local grocery store where I live. All of a sudden the owner tells me "Oh by the way you should know we don't give a tlush mascoret" to our workers I was quite shocked, naturally I didn't take the job. But is this legal? what would you do? Also what are the consequences of working in black if caught?
 
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