SB 10.66.38
sarvasyantar-bahih-saksi
krtyam mahesvarim vibhuh
vijñaya tad-vighatartham
parsva-stham cakram adisat
Translation:
The almighty Lord, the internal and external witness of all, understood that the monster had been produced by Lord Siva from the sacrificial fire. To defeat the demon, Krsna dispatched His disc weapon, who was waiting at His side.
Purport:
Srila Visvanatha Cakravarti comments that Lord Krsna, playing the part of a king, was absorbed in a gambling match and did not want to be disturbed by such an insignificant matter as the attack of a fiery demon. So He simply dispatched His cakra weapon and ordered him to take the necessary steps.