Garudapurana 1.136.9

1.136.9

vyāpakāya namaḥ kukṣau keśavāyodaraṃ budhaḥ /
trailokyapataye meḍhraṃ jaṅghe sarvabhṛte namaḥ //

The wise man [worships] the sides with “Obeisance to the Pervading One,” the belly with “To Keśava,” / the penis with “To the Lord of the three worlds,” and the shanks with “Obeisance to the Sustainer of all.”