Hadith 8:2836
Abu Bakr narrated to us, he said: Abd al-Wahhab narrated to us, he said: Ata was asked about the Umrah outside of the months of Hajj: Is there a mandatory sacrificial animal (hady) in it? He said: There is no mandatory sacrificial animal in it, and they used to offer sacrifices. The Prophet, may Allah bless him and grant him peace, offered a sacrifice when the polytheists obstructed him. Was he in the state of Ihram for Umrah? He said: Yes, and he made a peace treaty with them that he would come to them the following year. And I have seen Muawiyah slaughtering a camel during an Umrah outside of the months of Hajj.
حدثنا أبو بكر قال نا عبد الوهاب قال سئل عطاء عن العمرة في غير أشهر الحج فيها هدي واجب قال ليس فيها هدي واجب وقد كانوا يهدون وقد أهدى النبي صلى الله عليه وسلم حين صده المشركون فهل كان أحرم بالعمرة قال نعم وصالحهم أن يأتيهم في العام المقبل وقد رأيت معاوية ينحر جزورا في العمرة في غير أشهر الحج