Out Beyond The Ideas....

To me it means looking beyond the petty troubles of the day between people, cultures, society. When you look up at the clear night sky for example it leaves you with an overwhelming feeling and you're in awe of the universe. To get a different opinion I also found this-

"refers to something spiritual beyond the range of human perception.
The field is like a whole new field of consciousness so different than the thinking mind that sorts things into right and left, right and wrong, black and white.
Rumi is a rainbow of metaphors that point to a whole new way of seeing and experience life when our own sense of self importance begins to diminish and we look through eyes that were before encrusted with concepts"

because the next line of the poem does say-

"Ideas, language, even the phrase each other
doesn’t make any sense"

good .. nice !