And why beholdest thou the mote ... - A mote signifies any “light substance,” as dry chaff, or fine spires of grass or grain. It probably most usually signified the small “spiculae” or “beards” on a head of barley or wheat. It is thus placed in opposition to the word “beam.”
Beam - The word used here signifies a large piece of squared timber. The one is an exceedingly small object, the other a large one. The meaning is, that “we are much more quick and acute to judge of small offences in others, than of much larger offences in ourselves.” Even a very “small” object in the eye of another we discern much more quickly than a much larger one in our own; a small fault in our neighbor we see much more readily than a large one in ourselves. This was also a proverb in frequent use among the Jews, and the same sentiment was common among the Greeks, and deserves to be expressed in every language.