4:16 Go, gather . . . fast on my behalf. With conviction, faith, and fear, Esther directs that a fast (prayer always accompanied religious fasting, Deut. 9:9; Judg. 20:26, 27; Ezra 8:21–23; 2 Sam. 12:16; Dan. 9:3) be undertaken on her behalf. God honored the faith of the Jews at this time by saving them from destruction.
three days, night or day. Fasts generally were prescribed for only one day. This unusually long fast points to the seriousness of the situation and effectively contrasts with the feasts that stand at the beginning and end of the book (1:3, 5, 9; 2:18; 9:17–18).
against the law. Esther’s dilemma reintroduces the theme of obedience, since obedience to Mordecai meant disobeying the law.
if I perish, I perish. Courage, rather than passive resignation, is seen here (cf. Gen. 43:14).