Origen

Or, straining out a gnat, that is, putting from them small sins; swallowing a camel, that is, committing great sins, which He calls camels, from the size and distorted shape of that animal. Morally, The Scribes are those who think nothing else contained in Scripture than the bare letter exhibits; the Pharisees are all those who esteem themselves righteous, and separate themselves from others, saying, ‘Come not nigh me, for I am clean.’ Mint, anise, and cummin, are the seasoning, not the substantial part of food; as in our life and conversation there are some things necessary to justification, as judgment, mercy, and faith; and others which are like the seasoning of our actions, giving them a flavour and sweetness, as abstinence from laughter, fasting, bending the knee, and such like. How shall they not be judged blind who see not that it is of little avail to be a careful dispenser in the least things, if things of chief moment are neglected? These His present discourse overthrows; not forbidding to observe the little things, but bidding to keep more carefully the chief things.