Bhagavatapurana 12.9.25

12.9.25

cārv-aṅgulibhyāṃ pāṇibhyām unnīya caraṇāmbujam /
mukhe nidhāya viprendro dhayantaṃ vīkṣya vismitaḥ //

25. The great sage was astonished to see the child that with its hands of charming fingers, took hold of its own lotus-like foot and placed it in its mouth and sucked it.