Lord Vishnu points out to them that Hanuman is the better of them. They decide to try him out and prove their mastery.
At the appointed time, Bramha, Vishnu, Shiva, Narada, Tumburu and Hanuman gather.
To make the test interesting, Shiva freezes everyone in ice till their abdomen, with only their head and limbs movable.
The test is to melt the ice with your music and free yourself.
Both Narada and Tumburu fail, and Hanuman succeeds in thawing himself out.
After accepting his greatness, both Narada and Tumburu request Hanuman to free them too.
Upon their request, Hanuman sings and the soulful and celestial music melts the ice and both Narada and Tumburu are free.
But Hanuman is now in a different universe and continues to sing. The song is so powerful that Vishnu enters trance, and a part of his aura melts and trickles down to the feet.
Bramha promptly collects and stores the aura in his kamandala.
This aura of Vishnu melted by the divine and mellifluous song of devotee Hanuman, now collected by Bramha is Ganga.
Descent from heavens.
I’m cutting short the long story of Bhagirath’s ancestors’ cursed souls.
Pleased by Bhagirath’s penance to bring peace to his ancestors’ souls, Ganga agreed to descend from the heavens.
But the force for her descent would crush the earth and lead to devastating catastrophe. To prevent the same, Bhagirath started penance unto Shiva. Shiva is pleased with the penance and agrees to arrest Ganga’s descent of destruction.
When at the opportune moment Bramha releases Ganga from the heavens to the earth, Shiva is ready with his locks open to contain Ganga’s destructive dance.
In her arrogance, Ganga swelled up to cause maximum destruction but Shiva caught her in his locks and imprisoned her, to teach her a lesson.
Bhagirath was distraught and did penance unto Shiva a second time. Shiva softened and released Ganga, falling on the ground and flowing into 7 streams. 3 to the east, 3 to the west and one followed Bhagirath, who led the waters over his ancestors’ ashes and their souls were redeemed.
This having completed the incomparable task, Bhagirath brought Ganga to earth.
Bramha ordained that Ganga would also be known as Bhagirathi.
For the symbolism part, let’s look closer.
Ganga (Knowledge) flows from Shiva (God) to man (consciousness) to free the cursed souls (mind)
Knowledge has the power to enrich or crush you. Only the enlightened ones (Bhagirath) with their penance can bring the knowledge to the masses.