Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 31
Sanskrit:
न त्वया भीरुणा योत्स्ये युधि विक्लवतेजसा ।मथुरां स्वपुरीं त्यक्त्वा समुद्रं शरणं गत: ॥ ३१ ॥
ITRANS:
na tvayā bhīruṇā yotsyeyudhi viklava-tejasāmathurāṁ sva-purīṁ tyaktvāsamudraṁ śaraṇaṁ gataḥ
Translation:
“But I will not fight with You, Kṛṣṇa, for You are a coward. Your strength abandoned You in the midst of battle, and You fled Your own capital of Mathurā to take shelter in the sea.