https://www.scconline.com/blog/post/2020/11/18/ker-hc-if-a-particular-income-is-not-taxable-under-the-income-tax-act-it-cannot-be-taxed-on-the-basis-of-estoppel-or-any-other-equitable-doctrine-court-reiterates-principles-for-recovery-under-inc/