Abu Dawud Book 6, Hadith Number 2229.

Narated By ‘Aisha, Ummul Mu’minin : Al-Qasim said: ‘Aisha intended to set free two slaves of her who were spouses. She, therefore, asked the Prophet (PBUH) about this matter. He commanded to begin with the man before the woman. The narrator Nasr said: AbuAli al-Hanafi reported it to me on the authority of Ubaydullah.