Skandapurana 1.4.41.55

1.4.41.55

svaśarīramālabhet anena maṃtreṇa..
oṃkhakholkāya namaḥ..
saptavārānuccārya sthātavyam..
tena śuddhirupasaṃjāyate dehasyārcārhatā bhavati..
paścādāsanasthaṃ devaṃ savitāraṃ maṃḍalamadhye dvādaśātmakaṃ surādibhiḥ saṃpūjyamānaṃ dhyātvā pūrvoktamarghapātraṃ śirasi kṛtvā bhūmau jānunī nipātya sūryābhimukhastadgatamanābhūtvārghamaṃtramudāharet..
taducyate sūryavaktrādvinirgatamiti.. 43.55 ..

One should touch one's own body with this mantra: / 'Oṃ, homage to Khakholka.' / One should stand having recited it seven times. / By that, purification arises, and the body becomes fit for worship. / Afterward, having meditated upon the god Savitṛ seated on his seat in the middle of the maṇḍala, twelve-souled, being worshipped by the gods and others; having placed the previously mentioned arghya vessel on one's head; having lowered both knees to the earth; facing the sun with a mind fixed on him, one should utter the arghya mantra. / It is spoken as having issued from the mouth of the sun: