Once Allah's Messenger (ﷺ) went out to the Musalla (to offer the prayer) of `Id-al-Adha or Al-Fitr prayer.
Then he passed by the women and said, "O women! Give alms, as I have seen that the majority of the
dwellers of Hell-fire were you (women)." They asked, "Why is it so, O Allah's Messenger (ﷺ) ?" He replied,
"You curse frequently and are ungrateful to your husbands. I have not seen anyone more deficient in
intelligence and religion than you. A cautious sensible man could be led astray by some of you." The
women asked, "O Allah's Messenger (ﷺ)! What is deficient in our intelligence and religion?" He said, "Is not
the evidence of two women equal to the witness of one man?" They replied in the affirmative. He
said, "This is the deficiency in her intelligence. Isn't it true that a woman can neither pray nor fast
during her menses?" The women replied in the affirmative. He said, "This is the deficiency in her
religion."
Sahih al-Bukhari Book 6, Hadith 9
Allah's Messenger (ﷺ) entered upon me and said, "Have I not been informed that you offer prayer all the
night and fast the whole day?" I said, "Yes." He said, "Do not do so; Offer prayer at night and also
sleep; Fast for a few days and give up fasting for a few days because your body has a right on you,
and your eye has a right on you, and your guest has a right on you, and your wife has a right on you. I
hope that you will have a long life, and it is sufficient for you to fast for three days a month as the
reward of a good deed, is multiplied ten times, that means, as if you fasted the whole year." I insisted
(on fasting more) so I was given a hard instruction. I said, "I can do more than that (fasting)" The
Prophet said, "Fast three days every week." But as I insisted (on fasting more) so I was burdened. I
said, "I can fast more than that." The Prophet (ﷺ) said, "Fast as Allah's prophet David used to fast." I said,
"How was the fasting of the prophet David?" The Prophet (ﷺ) said, "One half of a year (i.e. he used to fast
on alternate days). '
Sahih al-Bukhari Book 78, Hadith 161