Skandapurana 14.21.10

14.21.10

.. sarasvatyuvāca ... ..
ahaṃ sarasvatī devī sadāsminvaraparvate..
niśāsukhe trayodaśyāṃ karomi vasatiṃ dvija ..
tasmāttvaṃ prārthaya varaṃ yadabhīṣṭaṃ sudurlabham .. 7.3.21.10 ..

Sarasvatī said: / I am Goddess Sarasvatī. On this excellent mountain, / I always make my dwelling at nightfall on the thirteenth day [of the lunar fortnight], O twice-born. / Therefore, ask for a boon, whatever is desired and hard to obtain.