At night they used to sit down together as friends and guests, and in the day they used to fight, risking life and death
SB Canto 1
The King, not received by any formal welcome by means of being offered a seat, place, water and sweet addresses, considered himself neglected, and so thinking he became angry.
The law of reception in the codes of the Vedic principles states that even if an enemy is received at home, he must be received with all respects. He should not be given a chance to understand that he has come into the house of an enemy. When Lord Kṛṣṇa, accompanied by Arjuna and Bhīma, approached Jarāsandha in Magadha, the respectable enemies were given a royal reception by King Jarāsandha. The guest enemy, namely Bhīma, was to fight with Jarāsandha, and yet they were given a grand reception. At night they used to sit down together as friends and guests, and in the day they used to fight, risking life and death. That was the law of reception. The reception law enjoins that a poor man, who has nothing to offer his guest, should be good enough to offer a straw mat for sitting, a glass of water for drinking and some sweet words. Therefore, to receive a guest, either friend or foe, there is no expense. It is only a question of good manners.
When Mahārāja Parīkṣit entered the door of Śamīka Ṛṣi, he did not expect a royal reception by the ṛṣi because he knew that saints and ṛṣis are not materially rich men. But he never expected that a seat of straw, a glass of water and some sweet words would be denied to him. He was not an ordinary guest, nor was he an enemy of the ṛṣi, and therefore the cold reception by the ṛṣi astonished the King greatly. As a matter of fact, the King was right to get angry with the ṛṣi when he needed a glass of water very badly. To become angry in such a grave situation was not unnatural for the King, but because the King himself was not less than a great saint, his becoming angry and taking action were astonishing. So it must be accepted that it was so ordained by the supreme will of the Lord. The King was a great devotee of the Lord, and the saint was also as good as the King. But by the will of the Lord, the circumstances were so created that they became ways to the King's becoming unattached to family connection and governmental activities and thus becoming a completely surrendered soul unto the lotus feet of Lord Kṛṣṇa. The merciful Lord sometimes creates such awkward positions for his pure devotees in order to drag them towards Himself from the mire of material existence. But outwardly the situations appear to be frustrating to the devotees. The devotees of the Lord are always under the protection of the Lord, and in any condition, frustration or success, the Lord is the supreme guide for the devotees. The pure devotees, therefore, accept all conditions of frustration as blessings from the Lord.