In the Vedas it is said, apo 'snati tan naivasitam naivanasitam. This Vedic injunction declares that the drinking of water may be accepted as eating or as not eating
SB Canto 9
The King said: "To transgress the laws of respectful behavior toward the brāhmaṇas is certainly a great offense. On the other hand, if one does not observe the breaking of the fast within the time of Dvādaśī, there is a flaw in one's observance of the vow. Therefore, O brāhmaṇas, if you think that it will be auspicious and not irreligious, I shall break the fast by drinking water." In this way, after consulting with the brāhmaṇas, the King reached this decision, for according to brahminical opinion, drinking water may be accepted as eating and also as not eating.
When Mahārāja Ambarīṣa, in his dilemma, consulted the brāhmaṇas about whether he should break the fast or wait for Durvāsā Muni, apparently they could not give a definite answer about what to do. A Vaiṣṇava, however, is the most intelligent personality. Therefore Mahārāja Ambarīṣa himself decided, in the presence of the brāhmaṇas, that he would drink a little water, for this would confirm that the fast was broken but would not transgress the laws for receiving a brāhmaṇa. In the Vedas it is said, apo 'śnāti tan naivāśitaṁ naivānaśitam. This Vedic injunction declares that the drinking of water may be accepted as eating or as not eating. Sometimes in our practical experience we see that some political leader adhering to satyāgraha will not eat but will drink water. Considering that drinking water would not be eating, Mahārāja Ambarīṣa decided to act in this way.