It is found in Bhagavad-gita: Although Krsna was doing everything for Arjuna, Arjuna never sat down idly as a nonviolent gentleman. Rather, he tried his best to fight the battle and be victorious

Expressions researched:
"This instruction is also found in Bhagavad-gītā. Although Kṛṣṇa was doing everything for Arjuna, Arjuna never sat down idly as a nonviolent gentleman. Rather, he tried his best to fight the battle and be victorious"

Srimad-Bhagavatam

SB Canto 10.1 to 10.13

Kṛṣṇa Himself is all-powerful, but it is not that a devotee should therefore sit idly and leave everything to Him. This instruction is also found in Bhagavad-gītā. Although Kṛṣṇa was doing everything for Arjuna, Arjuna never sat down idly as a nonviolent gentleman. Rather, he tried his best to fight the battle and be victorious.

SB 10.1.53, Translation and Purport

Vasudeva's mind was full of anxiety because his wife was facing danger, but in order to please the cruel, shameless and sinful Kaṁsa, he externally smiled and spoke to him as follows.

Sometimes one must act duplicitously in a dangerous position, as Vasudeva did to save his wife. The material world is complicated, and to execute one's duties, one cannot avoid adopting such diplomacy. Vasudeva did everything possible to save his wife for the sake of begetting Kṛṣṇa. This indicates that one may act duplicitously for the purpose of saving Kṛṣṇa and His interests. According to the arrangement already foretold, Kṛṣṇa was to appear through Vasudeva and Devakī to kill Kaṁsa. Vasudeva, therefore, had to do everything to save the situation. Although all the events were prearranged by Kṛṣṇa, a devotee must try his best to serve the purpose of Kṛṣṇa. Kṛṣṇa Himself is all-powerful, but it is not that a devotee should therefore sit idly and leave everything to Him. This instruction is also found in Bhagavad-gītā. Although Kṛṣṇa was doing everything for Arjuna, Arjuna never sat down idly as a nonviolent gentleman. Rather, he tried his best to fight the battle and be victorious.