The word ‘But’ connects this verse with the previous. Instead of giving what lies within us – love, mercy, kindness, gentleness – the Pharisees gave only things that could be seen, and they made sure that everyone noticed what they were giving.
So hypocrisy creates a false set of requirements, a replacement set of commandments that take the place of what God has really commanded. Do inventers of manmade religion really think that God will not notice what they have done? Do they imagine he will be indifferent to a few changes to his word? Do they think that his commandments as given do not really matter to him, and were only a rough guide to what he requires? Do they think that whole areas of obedience can be left out and God still be pleased with them? The love of the world can get back into the believer also. We may not say, ‘The Lord is unreasonable’, but we may look for another church that is not so serious on these things.