The Purity of the Exodus

The idea of holy nation over time triggered a zeal for purity. Could purity laws be seen in liberative terms as well? Are these two inherently in conflict with one another or do you see just a profound tension between the purity system in Israel and the story of the Exodus? Well, I think it's conceivable that purity could serve the well-being of the community but most often it turns out to be destructive.