Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 20
Sanskrit:
प्रतियाते तु देवर्षौ कंस आभाष्य केशिनम् ।प्रेषयामास हन्येतां भवता रामकेशवौ ॥ २० ॥
ITRANS:
pratiyāte tu devarṣaukaṁsa ābhāṣya keśinampreṣayām āsa hanyetāṁbhavatā rāma-keśavau
Translation:
After Nārada left, King Kaṁsa summoned Keśī and ordered him, “Go kill Rāma and Kṛṣṇa.”
Purport:
Before having Kṛṣṇa and Balarāma brought to Mathurā, Kaṁsa tried sending one more demon to Vṛndāvana.