Shiva Purana
आपोहिष्ठादिभिर्मन्त्रैः शेषमाघ्राय वै जलम् ॥ वामनासापुटेनैव देवं संभावयेत्सितम् ॥ १९ ॥
After chanting mantras such as āpohiṣṭha, one should smell the remaining water. One should meditate on the white god with the left nostril.
english translation
ApohiSThAdibhirmantraiH zeSamAghrAya vai jalam ॥ vAmanAsApuTenaiva devaM saMbhAvayetsitam ॥ 19 ॥
hk transliteration by Sanscript