1,404. Arriving Late; Reciting By Heart

Hilchos Megillah v’Chanukah 2:2

If a person enters shul and finds them half-way through the megillah, he should not stay to hear the second half with this congregation and then go back and read the first half himself because this is reading the megillah out of order. Rather, he must read the megillah in its entirety from start to finish in the proper order. If someone reads a section, takes a break, and then resumes reading, he fulfills his obligation because he read the megillah in order. This is so even if his break was long enough for the entire megillah to be read.

Hilchos Megillah v’Chanukah 2:3

If someone recites the megillah by heart, he does not fulfill his obligation. If someone who speaks a language other than Hebrew hears the megillah read in Hebrew from a scroll in Hebrew, he fulfills his obligation even if he doesn’t understand it. Similarly, if a megillah was written in Greek, one who hears it – even if he speaks Hebrew – fulfills his obligation even if he doesn’t understand it.