From the early Church Fathers to now.
“And when they had kept this watch for full twenty days, the cisterns, and the reserve of waters failed among all the inhabitants of Bethulia, so that there was not within the city, enough to satisfy them, no not for one day, for water was daily given out to the people by measure.”
“Days. Greek, “and all the collection of the Assyrians continued round them….thirty-four days.” (Haydock) — Old Vulgate, “twenty-four days.” Syriac, “two months and four days.” — Measure. Greek adds, “the infants, women, and young men fainted, and fell down dead.” (Haydock)”
The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.