Albert Barnes on Matthew 7:5

Thou hypocrite, first cast out, etc. Christ directs us to the proper way of forming an opinion of others, and of reproving and correcting them. By first amending our own faults, or casting the beam out of our eye, we can consistently advance to correct the faults of others. There will then be no hypocrisy in our conduct. We shall also see clearly to do it. The beam, the thing that obscured our sight, will be removed; and we shall more clearly discern the small object that obscures the sight of our brother. The sentiment is, that the readiest way to judge of the imperfections of others is to be free from greater ones ourselves. This qualifies us for judging, makes us candid and consistent, and enables us to see things as they are, and to make proper allowances for frailty and imperfection.

(t) "cast out the beam" Gal 6:1