Garudapurana 3.28.45

3.28.45

bṛhaspatirdevāgururmahātmā tasyāvatārāstraya āsan khagendra /
rāmāvatāre bharatākhyo babhūva hyaṃbhojajāveśayuto bṛhaspatiḥ //

Bṛhaspati, the noble preceptor of the gods, had three incarnations, O King of Birds:
in the Rāma incarnation, Bṛhaspati became the one named Bharata, endowed with the possession by the lotus-born [Brahmā].