Mbh 4.47.1a

Vaisampayana said, “King Duryodhana then, on the field of battle said unto Bhishma, and unto Drona--that tiger among warriors, and unto Kripa--that mighty car-warrior, these words, ‘Both myself and Karna had said this unto the preceptors.[54] I refer to the subject again, for I am not satisfied with having said it once. Even this was the pledge of the sons of Pandu that if defeated (at dice) they would reside to our knowledge in countries and woods for twelve years, and one more year unknown to us. That thirteenth year, instead of being over, is yet running. Vibhatsu, therefore, who is still to live undiscovered hath appeared before us. And if Vibhatsu hath come before the term of exile is at end, the Pandavas shall have to pass another twelve years in the woods. Whether it is due to forgetfulness (on their part) induced by desire of dominion, or whether it is a mistake of ours, it behoveth Bhishma to calculate the shortness or excess (of the promised period). When an object of desire may or may not be attained, a doubt necessarily attaches to one of the alternatives, and what is decided in one way often ends differently. [55] Even moralists are puzzled in judging of their own acts. [56] As regards ourselves, we have come hither to fight with the Matsyas and to seize their kine stationed towards the north. If, meanwhile, it is Arjuna that hath come, what fault can attach to us? We have come hither to fight against the Matsyas on behalf of the Trigartas; and as numerous were the acts represented unto us of the oppressions committed by the Matsyas, it was for this that we promised aid to the Trigartas who were overcome with fear. And it was agreed between us that they should first seize, on the afternoon of the seventh lunar day, the enormous wealth of kine that the Matsyas have, and that we should, at sunrise of the eighteen day of the moon, seize these kine when the king of the Matsyas would be pursuing those first seized.