Although the Supreme Personality of Godhead, the master of the demigods, was capable of performing the activities of the demigods by Himself, He wanted to enjoy pastimes in churning the ocean. Therefore He spoke as follows.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
एक एवेश्वरस्तस्मिन् सुरकार्ये सुरेश्वरः । विहर्तुकामस्तानाह समुद्रोन्मथनादिभिः
eka eveśvarastasmin surakārye sureśvaraḥ | vihartukāmastānāha samudronmathanādibhiḥ
SB 8.6.17