Matsya Purana — Ekoddiṣṭa Śrāddha
तत एकादशाहे तु द्विजानेकादशैव तु क्षत्रादिः सूतकान्ते तु भोजयेदयुजो द्विजान् //
tata ekādaśāhe tu dvijānekādaśaiva tu kṣatrādiḥ sūtakānte tu bhojayedayujo dvijān //
Then, on the eleventh day, one should feed eleven Brahmins; and for a Kṣatriya and the other varṇas, at the conclusion of the period of birth-impurity (sūtaka), one should feed Brahmins who are without physical defects, that is, ritually fit.
This verse does not address pralaya; it focuses on dharma concerning birth-impurity (sūtaka) and the prescribed feeding of Brahmins as a purificatory, merit-generating act.
It lays down a householder’s (and by extension a ruler’s) duty to observe sūtaka properly and to conclude it with sanctioned charity/feeding—specifically, feeding an appropriate number of Brahmins (eleven on the eleventh day) and ensuring the recipients are ritually fit.
The significance is ritual rather than architectural: it prescribes the timing (eleventh day/end of sūtaka), the number (eleven Brahmins), and the qualification of recipients (ayuja—unimpaired/fit), forming part of the Matsya Purana’s purity and expiation framework.