Skandapurana 5.189.51

5.189.51

tasmādvaraya bhadraṃ te yaṃ varaṃ manasi sthitam ..
sarvaṃ te'haṃ pradāsyāmi yadyapi syātsudurlabham .. 51 ..

Therefore, choose a boon—blessing be upon you—whatever boon rests in your mind. / I shall grant you everything, even if it is very difficult to obtain.”