Skandapurana 5.202

Ānarta said: / “O brahmin, tell me how a N膩gara, who has approached for purification / and stands before the Nāgaras, attains purification.”

Viśvāmitra said:

“When the assembly has become steady through the word of the arbiter, / he should be asked: ‘Tell us, which was your father’s mother?

Of what gotra was she? Who was her father, and what was his pravara remembered to be?’ / Having thus ascertained her lineage, along with gotra and pravara,

then her mother should be questioned, / and the mother who bore her should also be questioned,

and she too must be diligently investigated by the brahmins in the rite of purification.

The father, the paternal grandfather, and likewise the paternal great-grandfather— / these three of his must also be carefully verified.

Likewise on the paternal grandmother’s side, these three [generations], O best of brahmins; / then his maternal grandfather, that man's father, and whoever was his father;

the mother, the maternal grandmother, and likewise the one preceding her; / and the mother of the paternal grandmother must also be verified, along with her husband.

Having thus ascertained his tradition and lineage in due order, / extending on all sides from the root lineage like [the branches and roots of] a banyan tree,

purification should then be granted by applying a red-lead mark / and reciting benedictions in order, with the four-footed mantras.

Then, O best of kings, after giving three claps of the hands in front of him, / the arbiter should proclaim: ‘O king, this Nāgara brahmin is purified; / now this brahmin has become worthy of common status.’

Then, having gone to the fire sanctuary and propitiated the fire, / having offered the final full oblation with the five-faced mantra, / he should give a sacrificial fee to the brahmins according to his ability, accompanied by a meal.

When the red-lead mark has been applied before Brahmā by the word of the brahmins, / satisfaction arises among the ancestors: ‘Our lineage is established today.’

He whose purification through the branches belonging to the root lineage does not take place / must receive from the best of brahmins the restraint appropriate for a twice-born.”

In such a way that no other [unworthy one] may arise, his purification is ordained. / Thus purified, the brahmin then becomes fit for śrāddha rites. // 15

Even one born in the eight families, how much more so an ordinary one! / Indeed, for one who performs śrāddha and the like with an unpurified brahmin, / all of that becomes futile, like an oblation poured into ashes. // 16

Therefore, with every effort, this Nāgara brahmin must be purified, / for the purification of his own settlement and likewise of his own lineage. // 17

Thus ends the two hundred and third chapter, entitled 'Description of the Mode of Purification of Nāgaras', in the Māhātmya of the Hāṭakeśvara Sacred Field, in the Nāgarakhaṇḍa, the sixth [part] of the eighty-one-thousand-verse collection of the glorious Skanda Mahāpurāṇa. // 203