In Mahabharata, an great Hindu epic, Karna promised Kunti that she will always have five sons no matter what, by promising that he will only fight Arjuna and never kill the four others.
However, the context and circumstances surrounding this
promise are a bit more nuanced. Kunti, before her marriage, was given a boon by
Sage Durvasa, which allowed her to invoke any deity to have children. Without
knowing the consequences, Kunti tested the boon and invoked Surya, the sun god,
which resulted in the birth of Karna. Due to societal norms and personal
circumstances, Kunti had to abandon Karna, who was later raised by a
charioteer.
During the Kurukshetra War, when Karna learned about his
true parentage and relationship with the Pandavas (Kunti's other sons), he was
deeply moved. Despite being on the side of the Kauravas, he promised Kunti that
he would not kill any of her sons except Arjuna. This promise was out of
respect and love for his mother, despite his loyalty to Duryodhana, who was
leading the Kaurava army against the Pandavas.
However, it's worth noting that Karna's promise didn't
necessarily dictate the course of the war entirely. He fought valiantly against
the Pandavas, and the events of the war eventually led to Karna's confrontation
with Arjuna, where he was eventually slain by Arjuna. This event is one of the
most poignant moments in the Mahabharata, showcasing the complexities of
loyalty, duty, and familial bonds.