SB 1.9 - The inconceivable plan of the Lord
Bhīṣma confirms that no one can know the plan of the Lord and even though great philosophers and demigods like Brahmā and Śiva inquire exhaustively, they are still bewildered. It is best to simply abide by the orders of the Lord than to uselessly inquire about His plans. The Lord has to execute the plan of establishing the kingdom of virtue, and therefore His devotees suffered temporarily. Bhīṣma was satisfied to see the triumph of virtue. Even though he was a great devotee but he chose to fight against the Pāṇḍavas by the will of the Lord because the Lord wanted to show that even a great fighter like Bhīṣma cannot win on the wrong side.
No one may be aware of the plan of the Lord. Did he want to give the Pāṇḍavas suffering? It cannot be because then His quality of being affectionate to His devotee would be canceled. Did He want to give them joy? It cannot be because they had not seen any happiness. Did He want to give suffering and happiness? It cannot be because that would be a contradiction to His kind nature. So one cannot solve the problem by inquiry. Thus even those who use their intelligence to discriminate and those who use knowledge of scripture are bewildered by inquiry.
Bhīṣma asked Yudhiṣṭhira to accept the inconceivable plan of the Lord and take care of the subjects who had been rendered helpless. How can one not know the plan of the Lord when they could have asked the Lord, who was present at the moment right in front of them? In reply, Bhīṣma said that the Lord bewilders them with His energy. Even if asked by Bhīṣma, the Lord would not speak but instead evade him by answering ‘Am I so intelligent?’. Even if He said something, He would still bewilder everyone. Therefore His plan was to be followed and not subject to inquiry.