Bhagavatapurana 9.10.34

9.10.34

upagīyamānacaritaḥ śatadhṛtyādibhirmudā /
gomūtrayāvakaṃ śrutvā bhrātaraṃ valkalāmbaram //

34. 35. & 36. His heroic deeds were (then) joyfully sung by Brahma and others; Sri Rama heard that his brother Bharata wore bark and ate food dressed with Gomutra and, being most merciful, was very much pained to hear of him as wearing matted hair and sleeping