Yahya bin Sa'id (may Allah have mercy on him) said: I heard al-Qasim bin Muhammad (may Allah have mercy on him) saying: A woman came to Sayyiduna Ibn Abbas (may Allah be pleased with them both) and said: "I have vowed to slaughter my son." Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: "Do not slaughter your son, and expiate your oath." An elder who was sitting with Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: "How can there be expiation in this?" Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: Allah Almighty has said: "Those who pronounce zihar on their wives" [Surah al-Mujadilah: 3]. Then there is expiation in it, as you see.
(b) In the narration of Ja'far, the elder said: "How can there be expiation in obeying Satan?" He said: "Of course; does Allah not say" and he mentioned the same meaning.
This chain is sahih (authentic).
(c) Ikrimah (may Allah have mercy on him) narrates from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that he should slaughter a ram.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 20079