Mahabharata 4.6.12

4.6.12

yudhiṣṭhira uvāca |
āpto vivādaḥ paramo viśāṃ pate na vidyate kiṃcana matsya hīnataḥ |
na me jitaḥ kaścana dhārayeddhanaṃ varo mamaiṣo'stu tava prasādataḥ || 12 ||

Yudhishthira said, "My first prayer, O lord of earth, is that I may not be involved in any dispute (on account of dice) with low people.

[paragraph continues] Further, a person defeated by me (at dice) shall not be permitted to retain the wealth (won by me). Let this boon be granted to me through thy grace."