Bhagavatapurana 10.83.19

10.83.19

yathā svayaṃ-vare rājñi matsyaḥ pārthepsayā kṛtaḥ /
ayaṃ tu bahir ācchanno dṛśyate sa jale param //

19. O queen, just as in thy swayamvara it was done for the sake of Arjuna, the device of a fish was invented, but, this was co-

vered on the outside and was to be seen only reflected in water.