State tax filing

Thanks.  Can you point me to something that says that?  For example, ORS 316.127 discusses Oregon sources as the "items of income . . . that are derived from or connected to sources in this state."  Does anything in Oregon Code/regs say what "sources in this state" means? 

 

The idea that any income earned while in Oregon is Oregon source income is very counter-intuitive.  I'm the recipient of the income, not the source of it.  The source of it is my employer, which is in D.C.