After defeating the Pandavas in a game of dice, the Kauravas sent them in exile in the forest for 12 years and an additional year in living incognito. While the Pandavas were in the forest, the Kauravas along with their family members would visit the area where the Pandavas resided to display their prosperity and ridicule the poverty of Pandavas.
Along with his family members, once Duryodhana started his journey to a lake located in the forest. At that time, Chitrasen Gandharva along with his damsels, was enjoying sports in the same lake. On seeing Duryodhana, Gandharva objected to his coming to the lake. Dushasana was furious with this objection. In his anger, he challenged the Gandharvas to war. A ferocious war broke out between the two parties and it was the Gandharvas who had the upper hand. Gandharvas defeated the Kauravas. The Kauravas were in a deplorable state in front of the Gandharvas. Realising that their survival was difficult, 4-5 soldiers of the Kauravas somehow managed to escape and reached the forest where the Pandavas were camping. They approached Yudhishthir. They fell at his feet they requested him to save the honour of the Kuru family. Hearing this, Bhim said, “We will not do anything now. Let all Kauravas get destroyed at the hands of the Yaksha. The Kauravas, who are a thorn in the flesh, deserve to be eliminated. Without any effort we can achieve this”. But this opinion of Bhim was not acceptable to Yudhishthir. He said, “When we are fighting amongst ourselves it is okay for 5 Pandavas to fight against 100 Kauravas, but when it is a matter of fighting with outsiders, all 105 will fight together with the enemy and annihilate it completely. (Thus proving that ‘blood is thicker than water’ and internal differences should not prove useful to a common enemy)”
Convincing them, thus Yudhishthira got Bhim, Arjun, Nakul and Sahadev ready to fight the Gandharvas along with the Kauravas. The Pandavas joined the Kauravas in order to fight the Gandharvas and together they defeated the Gandharvas. While fighting the enemy they demonstrated “Vayam Panchadhikam Shatam”.
In this manner, even when there are innumerable mutual differences, the tendency to unite and fight an outsider (enemy) is known as “Vayam Panchadhikam Shatam”.