The word(s) "mature" appears 2 time(s) in 2 verse(s) in Quran in Mohsin Khan translation.

(1) And those of your women as have passed the age of monthly courses, for them the 'Iddah (prescribed period), if you have doubt (about their periods), is three months; and for those who have no courses [(i.e. they are still immature) their 'Iddah (prescribed period) is three months likewise, except in case of death] . And for those who are pregnant (whether they are divorced or their husbands are dead), their 'Iddah (prescribed period) is until they lay down their burden; and whosoever fears Allah and keeps his duty to Him, He will make his matter easy for him.

(2) And young full-breasted (mature) maidens of equal age,