Kansa informed by Nārada of the existence of Krishna and Balarāma; he sends Kesin to destroy them and Akrura to bring them to Mathura - Verse 11
Vishnu Purana (GRETIL; M. M. Pathak critical edition) · 4 · Verse 15.11
Sanskrit Original
तावच च भगवच्चक्रेणाशु व्यापादितस तेन तत्स्मरणदग्धाखिलाघसंचयो भगवतैवान्तम उपनीतस तस्मिन्न एव लयम उपययौ। एतत तवाखिलं मयाभिहितम। अयं हि भगवान कीर्तितः संस्मृतश च द्वेषानुबन्धेनाप्य अखिलसुरासुरादिदुर्लभं फलं प्रयच्छति किम उत सम्यग भक्तिमताम। वसुदेवस्यानकदुन्दुभेः पौरवीरोहिणीमदिराभद्रादेवकीप्रमुखा बह्व्यः पत्न्यो ऽभवन।।
tāvac ca bhagavaccakreṇāśu vyāpāditas tena tatsmaraṇadagdhākhilāghasaṃcayo bhagavataivāntam upanītas tasminn eva layam upayayau| etat tavākhilaṃ mayābhihitam| ayaṃ hi bhagavān kīrtitaḥ saṃsmṛtaś ca dveṣānubandhenāpy akhilasurāsurādidurlabhaṃ phalaṃ prayacchati kim uta samyag bhaktimatām| vasudevasyānakadundubheḥ pauravīrohiṇīmadirābhadrādevakīpramukhā bahvyaḥ patnyo 'bhavan||
Thus, by the divine wheel, the entire collection of sins was burned by the remembrance of Him, and He was brought to the ultimate state of dissolution. This is all that I have spoken to you. Indeed, the Lord, when remembered, grants the rare fruits even to those bound by enmity. Many wives of Vasudeva, including Devaki, were born.