Mbh 2.40.1c

Boasting as thou dost of virtue, in thy very sight, upon the widow of thy brother were sons begotten by another according to the ways of the honest. Where is thy virtue, O Bhishma? This thy celebacy, which thou leadest either from ignorance or from impotence, is fruitless. O thou who art conversant with virtue, I do not behold thy well-being. Thou who expoundest morality in this way dost not seem to have ever waited upon the old. Worship, gift, study,--sacrifices distinguished by large gifts to the Brahmanas,--these all equal not in merit even one-sixteenth part of that which is obtainable by the possession of a son. The merit, O Bhishma, that is acquired by numberless vows and fasts assuredly becomes fruitless in the case of one that is childless. Thou art childless and old and the expounder of false morality. Like the swan in the story, thou shalt now die at the hands of thy relatives. Other men possessed of knowledge have said this of old. I will presently recite it fully in thy hearing.