Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 46

Sanskrit:

वर्तमानोऽविदूरे वै बालोऽप्यजडधीरयम् ।न विस्मरति मेऽनार्यं शुन: शेप इव प्रभु: ॥ ४६ ॥

ITRANS:

vartamāno ’vidūre vaibālo ’py ajaḍa-dhīr ayamna vismarati me ’nāryaṁśunaḥ śepa iva prabhuḥ

Translation:

Although he is very near to me and is merely a child, he is situated in complete fearlessness. He resembles a dog’s curved tail, which can never be straightened, because he never forgets my misbehavior and his connection with his master, Lord Viṣṇu.

Purport:

The word śunaḥ means “of a dog,” and śepa means “tail.” The example is ordinary. However one may try to straighten a dog’s tail, it is never straight but always curved. Śunaḥ śepa is also the name of the second son of Ajīgarta. He was sold to Hariścandra, but he later took shelter of Viśvāmitra, Hariścandra’s enemy, and never left his side.