TT #29 · Parshas Tazria · Aliyah 1 · Passuk 4
English: She shall remain thirty-three days in the blood of her purification; she shall touch no consecrated thing and shall not enter the sanctuary until her days of purification are completed.
Chabad.org — Chumash, English translation + Rashi for Vayikra 12:4
Supplemental sources (three-page side ring): EXTRA 1 — Rashi, EXTRA 2 — Kerisos, and EXTRA 3 — Yevamos.
Torah Temimah cites Kerisos 10a.
E-Daf — Kerisos 10a · Shas.org — Kerisos 10a · Sefaria — Kerisos 10a
English: “And thirty days” — one might think the thirty days may be consecutive or scattered. Scripture says “day”: just as a day is wholly consecutive, so the thirty days must all be consecutive.
Textual analogy
The singular “day” supports a continuous thirty-day count: the required purification period is not accumulated from separate, scattered days.