Skandapurana 5.242.33

5.242.33

āṣāḍhaśuklaikādaśyāṃ kariṣye niyamaṃ gṛhe ..
nārāyaṇasya prītyarthaṃ śreyo'rthaṃ cātmanastathā ..
pratyuvāca munirdharmānvinayānatakandharam .. 33 ..

On the eleventh day of the bright half of Āṣāḍha, I will undertake my observance at home / for the pleasure of Nārāyaṇa and for the spiritual welfare of myself.' / Thus the sage, answering him whose neck was bowed with humility, explained the duties. [33]