It is narrated from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) that the Noble Prophet (peace and blessings of Allah be upon him) said: "O assembly of women, despite the deficiency and shortcoming in your religion and intellect, I have not seen anyone more capable than you of causing a wise man's intellect and composure to fly away." So they asked, "O Messenger of Allah, what is the deficiency in our religion and intellect?" He (peace be upon him) said: "Is not the testimony of a woman half that of a man?" They replied, "Yes, indeed." He (peace be upon him) said: "This is due to the deficiency and shortcoming in her intellect. And when a woman menstruates, does she not leave off prayer and fasting?" He (peace be upon him) said: "So this is the deficiency in her religion." This hadith is from Muhammad bin Yahya.