John Lightfoot on Luke 10:8

[Eat such things as are set before you.] The traditional canons were so very precise and curious about not eating unless what were clean, what had been duly tithed, and from which the Trumah had been duly separated, that it might be almost a wonder the strict traditionists should not be famished if they lived and fed only by canon. "Let not the religious serve at the table of a laic, unless all things be rightly prepared and decimated."

From the irksomeness and perplexity of this niceness doth our Saviour acquit and absolve his followers; partly that he might introduce the gospel liberty; partly also consulting the necessity of his disciples, who if they had been bound up to that strictness in meats, what could they do when their converse was to lie chiefly amongst persons perfectly unknown to them?