Srimad Bhagavatam Canto 01, Chapter 17, Text 17

SB 1.17.17

dharma uvaca
etad vah pandaveyanam
yuktam artabhayam vacah
yesam guna-ganaih krsno
dautyadau bhagavan krtah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The personality of religion said: These words just spoken by you befit a person of the Pandava dynasty. Captivated by the devotional qualities of the Pandavas, even Lord Krsna, the Personality of Godhead, performed duties as a messenger.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The assurances and challenges made by Maharaja Pariksit are never exaggerations of his real power. The Maharaja said that even the denizens of heaven could not escape his stringent government if they were violators of religious principles. He was not falsely proud, for a devotee of the Lord is equally as powerful as the Lord or sometimes more powerful by His grace, and any promise made by a devotee, though it may be ordinarily very difficult to fulfill, is properly executed by the grace of the Lord. The Pandavas, by their unalloyed devotional service and full surrender unto the Lord, made it possible for the Lord to become a chariot driver or sometimes their letter messenger. Such duties executed by the Lord for His devotee are always very pleasing to the Lord because the Lord wants to render service to His unalloyed devotee, whose life has no other engagement than to serve the Lord with full love and devotion. Maharaja Pariksit, grandson of Arjuna, the celebrated friendly servitor of the Lord, was a pure devotee of the Lord like his grandfather, and therefore the Lord was always with him, even from the time when he was helplessly lying in the womb of his mother and was attacked by the blazing brahmastra weapon of Asvatthama. A devotee is always under the protection of the Lord, and therefore the assurance of protection by Maharaja Pariksit could never be without meaning. The personality of religion accepted this fact and thus thanked the King for his being true to his exalted position.
Srimad Bhagavatam Canto 01, Chapter 17, Text 16
Srimad Bhagavatam Canto 01, Chapter 17, Text 18