SB 1.8 - Kṛṣṇa's will that Bhīṣma instruct Yudhiṣṭhira
Although Kṛṣṇa is the performer of superhuman feats, here He could not convince Yudhiṣṭhira. This does not mean the Lord failed but He desired this course of events. As Supersoul of Yudhiṣṭhira, He did not allow the king to be convinced by His words or Vyāsa’s because He desired the king hear the instructions from Bhīṣma, who was another great devotee. The Lord wanted that at the last stage of his life Bhīṣma see Him personally and see His beloved grandchildren now situated on the throne, and thus pass away peacefully. Bhīṣma had to take the side of the evil Duryodhana because he was maintained at the expense of Duryodhana. The Lord desired that Yudhiṣṭhira be pacified by the words of Bhīṣmadeva so that the world could see that Bhīṣma excelled all in knowledge. Vyāsa and other sages either knew or did not know this intention of the Lord. Kṛṣṇa made Yudhiṣṭhira completely incapable of understanding His own teachings and that of Vyāsa. The Lord wanted the world to know that Bhīṣma had more knowledge of dharma than Vyāsa, other sages or even Kṛṣṇa. But because Yudhiṣṭhira had even greater prema for Kṛṣṇa than Bhīṣma, Kṛṣṇa stayed back with him.
Yudhiṣṭhira became deluded by worldly affection by the will of the Lord, just as Arjuna was apparently deluded. A common man thinks of violence and non violence in terms of the body, but that is a kind of delusion. A kṣatriya is bound to fight for the right cause, and in such discharge of duty one should not be disturbed by annihilation of the material body. A man who sees knows well that the living entity is neither the body nor the mind but is transcendental to the material conception of life. The reason for Mahārāja Yudhiṣṭhira becoming deluded was the Lord willed he be instructed by Bhīṣma.