Praise be to Allaah.
Some of the female Sahaabah wished that they were men so that they could fight in jihaad for the sake of Allaah. Then Allaah revealed (interpretation of the meaning):
And wish not for the things in which Allaah has made some of you to excel others. For men there is reward for what they have earned, (and likewise) for women there is reward for what they have earned, and ask Allaah of His Bounty. Surely, Allaah is Ever All-Knower of everything [al-Nisaa 4:32]
Allaah forbade woman to wish for the things that are the exclusive preserve of men, for Allaah has given men a certain share of deeds in this world and they will have a corresponding share of reward in the Hereafter and the same applies to women. So ask Allaah, the Most Generous Bestower to give you of His bounty, instead of indulging in wishful thinking, for Allaah knows best what is suited to His slaves in the way in which He shares out good things among them.
Sheikh Muhammed Salih Al-Munajjid