Gopalacampu 1.22.31

1.22.31

[16] ajātāyāṃ ca tasyāṃ kṛṣṇayā taraṅga-kara-nikara-citam aharahar avakalitaṃ pulina-viśeṣam eva tad-ucitaṃ prabalam avakalayāmāsa |

And when it did not occur, [Kṛṣṇa] the younger brother of Bala recognized that a particular sandbank—layered with the hands of waves by the dark Yamunā and observed day after day—was especially powerful and suitable for that.