Skandapurana 1.4.40.162

1.4.40.162

nirmamatvaṃ tapaścātra santoṣaḥ saptamo hradaḥ..
bhagavadguṇavijñānādbhaktiḥ syātprathamā nadī.. 42.162 ..

Selflessness, austerity, and contentment is the seventh lake. / From discernment of the Lord's attributes, devotion is the first river;