6“Do not give dogs what is holy, and do not throw your pearls before pigs, lest they trample them underfoot and turn to attack you. ESV
Popular interpretations of this verse do not seem to fit well with its immediate context. Is Jesus offering a temper to his command not to judge, by saying there are some cases where judgement is necessary? It seems unlikely given his emphasis throughout the sermon on loving one's neighbour to the uttermost, and the immediately preceding verses (1-5) would seem to rule out an attitude that would consider someone a 'dog' or 'pig'.
I am suggesting that he is teaching that the Law condemns an attitude that would highlight one's perceived difference in moral standing with someone else; that to 'give dogs what is holy' or 'cast pearls before pigs' is such an action - as if I am setting the person up to fail, so I can say 'Did you see what they did with what I gave them? That just shows that they truly are unclean dogs/pigs!'