SB 10.89.62

niśāmya vaiṣṇavaṁ dhāma
 pārthaḥ parama-vismitaḥ
yat kiñcit pauruṣaṁ puṁsāṁ
 mene kṛṣṇānukampitam
Word for word: 
niśāmya — havīng seen; vaiṣṇavam — of Lord Viṣṇu; dhāma — the abode; pārthaḥ — Arjuna; parama — supremely; vismitaḥ — astonished; yat kiñcit — whatever; pauruṣam — special power; puṁsām — belonging to living beings; mene — He concluded; kṛṣṇa — of Kṛṣṇa; anukampitam — the mercy shown.
Translation: 
Having seen the domain of Lord Viṣṇu, Arjuna was totally amazed. He concluded that whatever extraordinary power a person exhibits can only be a manifestation of Śrī Kṛṣṇa’s mercy.
Purport: 

Śrīla Viśvanātha Cakravartī describes Arjuna’s amazement: He thought, “Just see! Even though I am a mere mortal, by Kṛṣṇa’s mercy I have seen the Supreme Godhead, the root cause of everything.” Then, after a moment, he thought again, “But why did Lord Viṣṇu say that he took away the brāhmaṇa’s children out of a desire to see Kṛṣṇa? Why would the Supreme Personality of Godhead hanker to see His own expansion? This might be the effect of some peculiar temporary circumstance, but since He said didṛkṣuṇā instead of didṛkṣatā — where the specific suffix ṣuṇā carries the sense of a permanent characteristic, not a temporary one — it has to be concluded that He has always been wanting to see Kṛṣṇa and myself. Even granted that this is so, why couldn’t He simply see Kṛṣṇa at Dvārakā? After all, Lord Mahā-Viṣṇu is the all-pervading creator of the universe, which He holds like an āmalaka fruit in His hand. Is it that He could not see Kṛṣṇa in Dvārakā because Kṛṣṇa does not allow anyone to see Him without His special sanction?

“And why, also, would Lord Mahā-Viṣṇu, the compassionate master of all brāhmaṇas, have repeatedly tormented an elevated brāhmaṇa, year after year? He must have acted in this unusual way only because He could not give up His extreme eagerness to see Kṛṣṇa. All right, He may have acted improperly for that reason, but why couldn’t He have sent a servant to kidnap the brāhmaṇa’s sons? Why did He Himself have to come to Dvārakā? Was stealing them out of Lord Kṛṣṇa’s capital so difficult that no one but Viṣṇu Himself could hope to accomplish it? I can understand that He intended to cause so much distress to a brāhmaṇa of Lord Kṛṣṇa’s city that Kṛṣṇa would be unable to tolerate it; then He would grant Lord Viṣṇu His audience. Lord Viṣṇu inspired the distressed brāhmaṇa to pour out his complaints to Kṛṣṇa in person. Thus it is clear that Śrī Kṛṣṇa’s status of Godhood is superior to Lord Mahā-Viṣṇu’s.”

Having thought in this way, Arjuna was totally amazed. He asked Lord Kṛṣṇa whether these were actually the facts of the matter, and the Lord replied, as related in the Hari-vaṁśa:

mad-darśanārthaṁ te bālā
 hṛtās tena mahātmanā
viprārtham eṣyate kṛṣṇo
 mat-samīpaṁ na cānyathā

“It was to see Me that He, the Supreme Soul, stole the children. He believed, ‘Only on a brāhmaṇa’s behalf will Kṛṣṇa come to see Me, not otherwise.’”

Śrīla Viśvanātha Cakravartī states that Lord Kṛṣṇa further told Arjuna, “I did not go there, however, for the brāhmaṇa’s sake; I went there, My friend, just to save your life. If it had been for the brāhmaṇa’s sake that I traveled to Vaikuṇṭha, I would have done so after his first child was abducted.”

According to Śrīla Śrīdhara Svāmī, although this pastime occurred before the Battle of Kurukṣetra, it is recounted here at the end of the Tenth Canto under the general heading of the supremacy of Lord Kṛṣṇa’s glories.