Adi Parva - Astika Parva 39

'Sauti said, 'King Janamejaya having said so, his ministers expressed
their approbation. And the monarch then expressed his determination to
perform a snake-sacrifice. And that lord of the Earth--that tiger of the
Bharata race--the son of Parikshit, then called his priest and Ritwiks.
And accomplished in speech, he spake unto them these words relating to
the accomplishment of his great task. 'I must avenge myself on the wretch
Takshaka who killed my father. Tell me what I must do. Do you know any
act by which I may cast into the blazing fire the snake Takshaka with his
relatives? I desire to burn that wretch even as he burnt, of yore, by the
fire of his poison, my father.'

'The chief priest answered, 'There is, O king, a great sacrifice for thee
devised by the gods themselves. It is known as the snake-sacrifice, and
is read of in the Puranas. O king, thou alone canst accomplish it, and no
one else. Men versed in the Puranas have told us, there is such a
sacrifice.'

"Sauti continued, 'Thus addressed, the king, O excellent one, thought
Takshaka to be already burnt and thrown into the blazing mouth of Agni,
the eater of the sacrificial butter. The king then said unto those
Brahmanas versed in mantras, 'I shall make preparations for that
sacrifice. Tell me the things that are necessary.' And the king's
Ritwiks, O excellent Brahmana, versed in the Vedas and acquainted with
the rites of that sacrifice measured, according to the scriptures, the
land for the sacrificial platform. And the platform was decked with
valuable articles and with Brahmanas. And it was full of precious things
and paddy. And the Ritwika sat upon it at ease. And after the sacrificial
platform had been thus constructed according to rule and as desired, they
installed the king at the snake-sacrifice for the attainment of its
object. And before the commencement of the snake-Sacrifice that was to
come, there occurred this very important incident foreboding obstruction
to the sacrifice. For when the sacrificial platform was being
constructed, a professional builder of great intelligence and well-versed
in the knowledge of laying foundations, a Suta by caste, well-acquainted
with the Puranas, said, 'The soil upon which and the time at which the
measurement for the sacrificial platform has been made, indicate that
this sacrifice will not be completed, a Brahmana becoming the reason
thereof.' Hearing this, the king, before his installation, gave orders to
his gate-keepers not to admit anybody without his knowledge."