Mahabharata 9.36.55

9.36.55

tatra kuñjānbahūndṛṣṭvā saṃnivṛttāṃ ca tāṃ nadīm |
babhūva vismayastatra rāmasyātha mahātmanaḥ || 55 ||

And they made that foremost of rivers exceedingly beautiful, like the celestials beautifying (with their presence) the heavenly stream called Mandakini. Hundreds upon hundreds of Rishis, all given to the observance of sacrifices, came thither. Those practisers of high vows, however, failed to find sufficient room on the banks of the Sarasvati. Measuring small plots of land with their sacred threads, they performed their Agnihotras and diverse other rites. The river Sarasvati beheld, O monarch, that large body of Rishis penetrated with despair and plunged into anxiety for want of a broad tirtha wherein to perform their rites. For their sake, that foremost of streams came there, having made many abodes for herself in that spot, through kindness for those Rishis of sacred penances, O Janamejaya! Having thus, O monarch, turned her course for their sake, the Sarasvati, that foremost of rivers, once more flowed in a westerly direction, as if she said, 'I must go hence, having prevented the arrival of these Rishis from becoming futile!' This wonderful feat, O king, was accomplished there by that great river. Even thus those receptacles of water, O king, were formed in Naimisha. There, at Kurukshetra, O foremost of Kuru's care, do thou perform grand sacrifices and rites! As he beheld those many receptacles of water and seeing that foremost of rivers turn her course, wonder filled the heart of the high-souled Rama.