Skandapurana 6.3.48.25

6.3.48.25

śrībhagavānuvāca -
tuṣṭaste dānavendrāhaṃ varaṃ vṛṇu yathepsitam .
dadāmi te varaṃ nūnamapi trailokyadurlabham .. 48.25 ..

The Blessed Lord said:
I am pleased with you, O lord of Dānavas; choose a boon as you desire.
I shall certainly give you a boon, even one difficult to obtain in the three worlds.