Brahma Sutras
ॐ संस्कारपरामर्शात्तदभावाभिलापाच्च ॐ ॥ १-३-३६॥
Because purificatory rites are mentioned (for others) and absence of these is declared (for the Sudra).
english translation
OM saMskAraparAmarzAttadabhAvAbhilApAcca OM ॥ 1-3-36॥
hk transliteration by Sanscript