SB 10.71.7
brahma-vesa-dharo gatva
tam bhikseta vrkodarah
hanisyati na sandeho
dvai-rathe tava sannidhau
Translation:
Bhima should go to him disguised as a brahmana and beg charity. Thus he will obtain single combat with Jarasandha, and in Your presence Bhima will no doubt kill him.
Purport:
The idea is that Bhima should beg as charity a one-to-one fight with Jarasandha.