The Divine Descent of Ganga
Neither King Amshuman nor his son, King Dileep, was able to bring Ganga to cleanse their ancestors. But King Bhageerath, Dileep's son, managed to do this through his fervent devotion and prayers. For this reason, Ganga is also called Bhageerathi.
Lord Brahma informed Bhageerath that only Lord Shiv had the power to withstand the immense force with which Ganga would descend to the earth. So, Brahma advised Bhageerath to seek Shiv’s help. In response to Bhageerath's prayers, Shiv agreed to control the speed at which Ganga would reach the earth.
As Ganga descended, Shiv untied and spread his hair. After Ganga filled up Shiv’s hair, he retied it in a knot. Soon, Ganga began to flow out of Shiv’s hair at a steady speed.
During Ganga's journey on the earth, she happened to disturb Rishi Jahnu's meditation. The angry rishi drank up the entire river. But, upon the gods' request, Rishi Jahnu let Ganga flow out of his ear. Hence, Ganga has another name: Jahnavi, meaning "daughter of Jahnu."
Thus, Ganga came to the earth and liberated Bhageerath's ancestors.