Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 14: The Aśvamedha Sacrifice
Text 1.14.28

इष्टकाश्च यथान्यायं कारिताश्च प्रमाणतः।
चितोऽग्निर्ब्राह्मणैस्तत्र कुशलैः शुल्बकर्मणि॥

iṣṭakāś ca yathā-nyāyaṁ kāritāś ca pramāṇataḥ
cito
gnir brāhmaṇais tatra kuśalaiḥ śulba-karmaṇi

iṣṭakāḥ ca = special bricks; yathā-nyāyaṁ = as per scripture; kāritāḥ ca = were made; pramāṇataḥ = according to the right measurement; citaḥ = altar; agniḥ = the fire; brāhmaṇaiḥ = was prepared using those bricks by brāhmaṇas; tatra = there; kuśalaiḥ = expert; śulba-karmaṇi = in sacrificial work.

Special bricks were made according to the right measurement as per scripture. The fire altar was prepared using those bricks by brāhmaṇas there expert in sacrificial work.

Śulba-karmaṇi indicates that the brāhmaṇas were expert in sacrificial rites [9]. The rites specifically pertain to piling of bricks and arranging the sacrificial altar through a śulba or a measuring string [10].1 Special bricks were created for this purpose [11].

[9] śulbaṁ tāmre yajna-karmaṇy ācāre jala-sannidhau. (Vaijayantī)

[10] rajjūnāṁ viharaṇa-sādhanatvād etat karma śulbam ācaṣṭa ācāryaḥ. (Haradatta)

[11] pāda-mātro ’rdha-mātro ’ṇuka-mātra ṛju-rekhā dakṣiṇāvṛtā savyāvṛtā stryā likhitāś ca. (Āpastamba Śrauta-sūtra)

1 The Śulba-sūtras present formulae for creating the geometric shapes of the sacrificial altars and so on.