"Men are overseers over women, by reason of that wherewith Allah hath made one of them excel over another, and by reason of that which they expend of their substance. Wherefore righteous women are obedient, and are watchers in husbands absence by the aid and protection of Allah. And those wives whose refractoriness ye fear, exhort them, and avoid them in beds, and beat them; but if they obey you, seek not a way against them; verily Allah is ever Lofty, Grand." - Quran 4:34 (read more)

"Narrated Abdullah ibn AbuDhubab: Iyas ibn Abdullah ibn AbuDhubab reported the Apostle of Allah (peace be upon him) as saying: Do not beat Allah's handmaidens, but when Umar came to the Apostle of Allah (peace be upon him) and said: Women have become emboldened towards their husbands, he (the Prophet) gave permission to beat them." - Sunan Abu Dawud 11:2141 (read more)

"The actual example of one of the greatest Companions, `Ali ibn Abi Talib (may Allah be pleased with him) gives credit to this [death sentence for apostasy] also. He himself carried out the punishment on some people who had deified him. He gave them three days respite to repent and go back to their senses. When they proved adamant, he put them to fire." - IslamOnline