SB 5.12.14
aham pura bharato nama raja
vimukta-drsta-sruta-sanga-bandhah
aradhanam bhagavata ihamano
mrgo ’bhavam mrga-sangad dhatarthah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In a previous birth I was known as Maharaja Bharata. I attained perfection by becoming completely detached from material activities through direct experience, and through indirect experience I received understanding from the Vedas. I was fully engaged in the service of the Lord, but due to my misfortune, I became very affectionate to a small deer, so much so that I neglected my spiritual duties. Due to my deep affection for the deer, in my next life I had to accept the body of a deer.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The incident herein described is very significant. In a previous verse it is stated, vina mahat-pada-rajo-’bhisekam: one cannot attain perfection without smearing the dust from the lotus feet of an exalted devotee on his head. If one always follows the orders of the spiritual master, there is no question of falling down. As soon as a foolish disciple tries to overtake his spiritual master and becomes ambitious to occupy his post, he immediately falls down. Yasya prasadad bhagavat-prasado yasyaprasadan na gatih kuto ’pi. If the spiritual master is considered an ordinary man, the disciple surely loses his chance to advance further. Despite a very rigid life in devotional service, Bharata Maharaja did not consult a spiritual master when he became overly attached to a deer. Consequently he became strongly attached to the deer, and, forgetting his spiritual routine, he fell down.