Srimad Bhagavatam Canto 11, Chapter 17, Text 45

SB 11.17.45

sarvah samuddhared raja
 piteva vyasanat prajah
atmanam atmana dhiro
 yatha gaja-patir gajan
 
Translation: 
 
Just as the chief bull elephant protects all other elephants in his herd and defends himself as well, similarly, a fearless king, just like a father, must save all of the citizens from difficulty and also protect himself.
 
Purport: 
 
Lord Krsna, having concluded His discussion of brahminical duties, now describes the character and activities of a king. Protecting all of the citizens from difficulty is an essential duty for the king.
Srimad Bhagavatam Canto 11, Chapter 17, Text 44
Srimad Bhagavatam Canto 11, Chapter 17, Text 46