One verse

Srimad Bhagavatam 6.8.7

6.8.7

करन्यासं तत: कुर्याद् द्वादशाक्षरविद्यया । प्रणवादियकारान्तमङ्गुल्यङ्गुष्ठपर्वसु ॥ ७ ॥

kara-nyasam tatah kuryad dvadasaksara-vidyaya pranavadi-ya-karantam anguly-angustha-parvasu

kara-nyasam
the ritual known as kara-nyasa, which assigns the syllables of the mantra to the fingers
tatah
thereafter
kuryat
should execute
dvadasa-aksara
composed of twelve syllables
vidyaya
with the mantra
pranava-adi
beginning with the omkara
ya-kara-antam
ending with the syllable ya
anguli
on the fingers, beginning with the index finger
angustha-parvasu
to the joints of the thumbs.

Then one should chant the mantra composed of twelve syllables (om namo bhagavate vasudevaya). Preceding each syllable by the omkara, one should place the syllables of the mantra on the tips of his fingers, beginning with the index finger of the right hand and concluding with the index finger of the left. The four remaining syllables should be placed on the joints of the thumbs.