In plain words
So the second instrument is the tongue. We must guard it with great care. So it is essential to weigh sacred words, consider them and think a little before using the tongue. In some emotion or excitement you may use words of one kind or another. But there will always be Reaction, Resound and Reflection to them. So we must guard our speech with great care. Wherever we go, we must nurture our speech in the right way. We must use words that hurt no one's heart. “Slip with the foot and there is no loss; slip with the tongue and it is hell,” they have said. If we slip and fall, we get some small hurt. That hurt can be seen by the eye. Whatever doctor we go to, we can ask him for help, put on a bandage, take medicine and heal it. But when the tongue slips, no one can see where the heart has been hurt. No one can see it. No doctor can heal it. Your punishment will heal you. So, before you have to suffer punishment, take the medicine called repentance and cure it. What has happened has happened. You must make the right effort to reshape yourself in a sacred way through repentance. So in the matter of the tongue we must take the greatest care.
Brahmavit brahmaiva bhavati
We must never speak ill of anyone to others. We must never talk of anyone's weaknesses. Why? What right have you? Where is your right to point out the faults of others, when you keep any number of faults in yourself? Look at your own fault and make the effort to set it right. With a great beam stuck in his own eye, writhing in pain, this fellow, they say, points out the mosquito beside him! When any number of faults are rotting and wasting away in you, you have no right to ignore them and pass judgement that others are like this and like that.