When nectar did not come from the Ocean of Milk, despite so much endeavor by the best of the demigods and demons, the Supreme Personality of Godhead, Ajita, personally began to churn the ocean.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
मथ्यमानात्तथा सिन्धोर्देवासुरवरूथपैः । यदा सुधा न जायेत निर्ममन्थाजितः स्वयम्
mathyamānāttathā sindhordevāsuravarūthapaiḥ | yadā sudhā na jāyeta nirmamanthājitaḥ svayam
SB 8.7.16