As I ask in this Question about some of my doubts in reference to the Mṛta Sanjeevani Mantra (मृत संजीवनी मंत्र), similarly, there have been several instances when sages have been able to revive the "apparently" dead people just via their penance aggregated austerities (tapas).
Some examples are:
- Revival of Kavyamāta by Bhṛgu Rishi
- Revival of Renukā (Parshurām's mother) by Jamadagni
- And several other
So, my question is, what's the significance to specifically obtain the Mṛta Sanjeevani Mantra Vidyā, when sages are very well in possession of the powers (due to their tapasyā) to revive dead people (in some cases, despite getting "beheaded" by Vishnu himself or his aṃśa avatāra)?