“He (Vidura) indirectly hinted, ‘A weapon not made of steel or any other material element can be more than sharp to kill an enemy, and he who knows this is never killed.’ That is to say, he hinted that the party of the Pandavas was being sent to Varanavata to be killed, and thus he warned Yudhishthira to be very careful in their new residential palace.” (Shrila Prabhupada, Shrimad Bhagavatam, 1.13.8 Purport)