parsha bit: B'midbar

The rabbis ask why the torah was given in the midbar, the wilderness. One commonly-cited answer is that it was given in a place not claimed by anyone to show that the torah is available to all. Another is that it was to teach us about openness: just as the desert is open to all influences, so must we be open if we are to adopt torah. We must be open to new perspectives and ready to examine and experiment with others' interpretations rather than closing our minds and thinking we know the truth. (Pesikta d'Rav Kahanah 107a)

I'd love to know the context for this one; I saw this passage quoted in another source but don't have the original.

(I didn't actually give this one today; I deferred to someone else in leading the service.)