Vasishthadharmasutra 11.77

11.77

dvau māsau yāvakena vartayet^māsam payasārdhamāsam āmikṣayāṣṭarātram ghṛtena ṣaṭrātram ayācitena trirātram abbhakṣas aharrātram upavaset //

Let him subsist during two months on barley-gruel, during one month on milk, during half a month on curds of two-milk whey, during eight days on clarified butter, during six days on alms given without asking, (and) during three days on water, and let him fast for one day and one night.