The hardness of flint is known to none so well as to those who strike it. I offer myself to all attacks, like some lonely rock in a shallow sea, which the waves never cease to beat upon from whatever quarter they may come, but which they cannot thereby move from its place nor yet wear away, for however many years they may unceasingly dash against it. Bound upon me, rush upon me, I will overcome you by enduring your onset: whatever strikes against that which is firm and unconquerable merely injures itself by its own violence. Wherefore, seek some soft and yielding object to pierce with your darts. But have you leisure to peer into other men's evil deeds and to sit in judgment upon anybody? To ask how it is that this philosopher has so roomy a house, or that one so good a dinner? Do you look at other people's pimples while you yourselves are covered with countless ulcers? This is as though one who was eaten up by the mange were to point with scorn at the moles and warts on the bodies of the handsomest men. Source

1 “Do not judge so that you will not be judged. 2 For by the standard you judge you will be judged, and the measure you use will be the measure you receive. 3 Why do you see the speck in your brother’s eye, but fail to see the beam of wood in your own? 4 Or how can you say to your brother, ‘Let me remove the speck from your eye,’ while there is a beam in your own? 5 You hypocrite! First remove the beam from your own eye, and then you can see clearly to remove the speck from your brother’s eye. Source