Read this post about an introduction to the Rasas.
After the Pandava brothers completed their exile of 12 yrs and the 13th year in disguise evading all attempts by the Kauravas in trying to find out where they were during this year, they came out of exile and temporarily settled down in Upalavya. From there Yudhisthira send out emissaries to summon all his friends, relatives and brethren, to which almost all responded and arrived.
Addressing the gathering, Krishna spoke and reminded the people present as to how Duryodhana and Shakuni had cheated Yudhisthira at the game of dice and sent the Pandava brothers to exile for the past 13 yrs. He went on to state that Yudhisthira did not want to spill the blood of his cousins and wanted only what was rightfully his share of the kingdom. Despite the fact that the Kauravas had treated them wrongly and had cheated them out of their rights, the Pandavas were magnanimous to treat their cousins with ‘dharma’ and did not hold any grudges against them. He then went on to state that it was the intention of Yudhisthira to send an envoy of peace to the Kauravas to ask for their rightful share of the kingdom.
However, despite multiple attempts by the Pandavas to find a peaceful solution to the issue, Duryodhana refused to budge from his position. He steadfastly refused to recognize the right of the Pandavas to the kingdom and even went to the extent of declaring in open court that the Pandavas will not receive a needle-point of territory from him. Even after this declaration, Yudhisthira maintained his calm despite protests from his own brothers, kinsmen and other friends, and sent Krishna as an envoy of peace to convince Duryodhana of the mistake of his actions.
Thus, despite being cheated by the Kauravas out of his share of the kingdom, despite the fact that Duryodhana and his brothers had humiliated him and his brothers, despite the fact that they had tried to disrobe his wife in open court, Yudhisthira maintained his efforts to find a peaceful solution to this issue. This is a classic example of the santha rasa being referred to in the Mahabharata.