As turns by taking a great oath, which is a complete sacrifice favoring his parents, the king of , became bewildered and out of love and affection for his son, he delivered the iccha mrityu boon to his son –
O Son, You will die only at your wish. No one, not even Yama, the god of Death can claim your life, unless you wish to hand it over to him.
Caliber of the iccha mrityu boon
This boon is in fact the greatest boon delivered in the entire Shantanu, who is a mere Human deliver such a boon like iccha mrityu, which is like onto the boon to be immortal, which even Brahma and Vishnu fails to provide?and many readers even put a claim that how can
How the iccha mrityu boon can be delivered
Hey readers, I could have said the answer promptly that the Mahabharata is an epic and that is meant to give us lesson only, but that will not be a right answer now, since evidences and proofs are all supporting the discoverers and historians to conclude that Mahabharata was 100% real incidence. They even dated the total epic and now it is not an epic at all, but an Historic real incidence.
So, the only thing that can be said in reply to your question is – First of all Shantanu was the father of Bhishma and Hinduism provides the power of Shiva to a father (of course to his son) and the second thing I can say here is that, Shantanu was not a mere human. One who have reached the Pitri Loka, for his great acts, surely gains some power in him, which is not like that of a common Human. Make a point that in Hinduism, Pitri Loka is referred with Muladhar of Kundalini. Hence, he was a person with awakened Kundalini.
And about the fact that Brahma and Vishnu didn’t deliver the boon to be immortal is not their boundary of power, but the boundary of ethics. Since, their duty in the Government of Universe is confined to Creation and protection, hence they do not interfere on Contamination affairs like delivering iccha mrityu Boon by a father to his son- that’s it.