Mahabharata Karna parva Chapter 38:2

Mahabharata Karna parva Chapter 38:2 To him that will discover Dhananjaya to me, I shall also give a hundred female slaves, with golden collars, belonging to the country of the Magadhas, and of very youthful age. If that does not satisfy the person that discovers Arjuna to me, I will make him a more valuable gift, that, indeed, which he himself will solicit. Sons, wives and articles of pleasure and enjoyment that I have, these all I shall give him if he desires them. Indeed, unto him who discovers Keshava and Arjuna to me, I shall, after slaying those two, give all the wealth that may be left by them." Having uttered those diverse speeches in that battle, Karna blew his excellent conch, sea-born and producing a sweet blare. Hearing these words of Suta's son that were suitable to his disposition, Duryodhana, O king, with all his followers became filled with joy. At that juncture the beat of cymbals and drums and leonine shouts, and grunts of elephants with the sounds of diverse musical instruments, arose there, O king, among the (Kaurava) troops, O bull among men. The shouts also of warriors filled with joy arose there. When the (Kaurava) troops were thus filled with joy, the ruler of the Madras, laughing in scorn, said these words unto that grinder of foes, viz., the son of Radha, that mighty car-warrior who was about to plunge into that ocean of battle and who was indulging in such vain bragging.'"