Shami tree is called ‘Agni garbha’, one that holds fire in its core. But, doesn’t every tree hold fire? Why is only Shami tree called ‘agni garbha’. Other trees produce fire upon friction with with each other during hot summers in the presence of high winds. Whereas Shami tree log when churned with Peepal (ashwatth) tree log produces fire that is rightly apt to be used in all Vedic rituals involving Yajna. However, not all Shami trees can be used in this purpose. Only the Shami tree that gives birth to Peepal tree within itself can be used; and both the trees must both be growing together as one unit. The logs from such two trees become the right inputs to the desired output of the ‘Yajna’.