Devibhagavatapurana 3.18.24

3.18.24

āśīrvādaiśca vo nūnaṃ putro'yaṃ me mahīpatiḥ |
bhaviṣyati na sandeho bhavanto mantravittamāḥ ||

You are the best of the knowers of mantrams; due to the influence of your good will, my son will surely be a king; there is no doubt in this.”