Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 68

Sanskrit:

एवं सभाजितो गोपै: कृष्णभक्त्या नराधिप ।उद्धव: पुनरागच्छन्मथुरां कृष्णपालिताम् ॥ ६८ ॥

ITRANS:

evaṁ sabhājito gopaiḥkṛṣṇa-bhaktyā narādhipauddhavaḥ punar āgacchanmathurāṁ kṛṣṇa-pālitām

Translation:

[Śukadeva Gosvāmī continued:] O ruler of men, thus honored by the cowherd men with expressions of devotion for Lord Kṛṣṇa, Uddhava went back to the city of Mathurā, which was under Kṛṣṇa’s protection.

Purport:

The word kṛṣṇa-pālitām indicates that even though Uddhava became quite attached to the land of Vṛndāvana, he returned to Mathurā because Śrī Kṛṣṇa was personally displaying His transcendental pastimes there.