Mahabharata 2.38.40

2.38.40

antarātmani vinihite rauṣi patraratha vitatham |
aṇḍabhakṣaṇamaśuci te karma vācamatiśayate || 40 ||

"Thy behaviour, O Bhishma, is even like that of the old swan. These lords of earth might slay thee in anger like those creatures of the feathery tribe slaying the old swan. Persons conversant with the Puranas recite a proverb, O Bhishma, as regards this occurrence, I shall, O Bharata, repeat it to thee fully. It is even this: O thou that supportest thyself on thy wings, though thy heart is affected (by the passions), thou preachest yet (of virtue); but this thy sinful act of eating up the eggs transgresseth thy speech!"