The Ocean of Mantras

Using the thumb and ring finger, one should take the kusha grass and cast it.
One should perform the purification of the ghee three times facing the fire with the weapon-mantra. (172)
In the same way, one should perform the samplava mixing of the ghee towards oneself with the heart-mantra.
During the purification rites, one should place the kusha grass into the fire. (173)
One should place three kusha grass blades with a knot into the center of the ghee.
Remembering the left and right sides, one should contemplate the three channels.
The wise one, having taken the ghee from the right, left, and middle, with the heart-mantra. (174)
One should offer "Agnaye Agnipriya" and "Somaya Svaha" into the two eyes of the fire.
One should offer "Agnishomabhyam Svaha" into the third eye. (175)
One should let the remainder of the offering fall into the place of offering.
Again, having taken ghee from the right side with the heart-mantra, one should offer into the mouth. (176)
"Agnaye Svishtakrite" is considered the opening of the eyes.
Except for Narasimha, for all Vishnu mantras, one should worship the two eyes. (177)
For deities other than Narasimha, three eyes of fire are remembered.
One should perform four offerings with the great utterances, separately and together. (178)
One should then perform three offerings with the fire-mantra itself.
With eight ghee offerings, one should perform each purification rite. (179)
"Om, I perform this rite of conception for this Fire, O Beloved of Fire."
Muttering the mantra thus, one should perform the rites of impregnation, male-progeny, (180)
Hair-parting, and birth-rites, and then proceed.
Five stick-offerings in the fire and the final disposal of the offerings. (181)

The Go-mudra refers to the Dhenu-mudra (167-173). The three channels: Ida, Pingala, and Sushumna, which should be contemplated in the middle (174). With the mantra "Hrid Namah," offer "Agnaye Svaha" into the right eye and "Somaya Svaha" into the left. These four offerings lead to the illumination of the fire's eyes. Then "Om, I perform the conception rite for this fire, Svaha," etc. (175-180).