Ata bin Abi Rabah (may Allah have mercy on him) narrates from Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) that he was asked about a man in ihram, at Mina, who has intercourse with his wife before the Tawaf al-Ifadah. He ordered him to sacrifice a camel.
Imam al-Shafi'i (may Allah have mercy on him) said: This is what we adopt. Imam Malik (may Allah have mercy on him) said: An Umrah and the sacrifice of a camel are due from him, and his Hajj is complete.
(b) He (Malik) narrated it from Rabi'ah (may Allah have mercy on him), and so he left the saying of Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) for the opinion of Rabi'ah.
And he narrated it from Thawr bin Zayd, from Ikrimah, thinking it to be from Ibn Abbas, while he (Malik) speaks ill of Ikrimah and does not consider that anyone should accept his hadith; yet he narrates with certainty from Ata, from Ibn Abbas, the opposite of it, and Ata is trustworthy in his view and in the view of the people. The Shaykh said: We have also narrated it from the jurists of the people of Madinah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9803