1994 Mercedes E320 wagon intake manifold hose nipple goes where?

[dmorgan]

I am doing some repair work on my 1994 Mercedes E320 wagon. I removed the throttle body and reasonance valve. After that, I noticed this dangling rubber hose connected to the underneath of the intake maifold.
There are two nipple hoses. The one facing me on the right in front of the intake manifold goes somewhere. The one on the left goes to the air/smog compressor behind the radiator on the lower right side facing me. Does anyone knows where this hose on the right connected to? Feedback/comments is greatly appreciated.