Abd al-Rahman bin Abi Layla (may Allah have mercy on him) said: I was present with Sayyiduna Ali (may Allah be pleased with him); he made a man who had taken an oath of ila stand after four months. He said: He made him stand in a raised place and said: Either take your wife back or divorce her.
This chain is sahih (authentic) and connected.
(b) Abu al-Bakhtari (may Allah have mercy on him) narrates from Sayyiduna Ali (may Allah be pleased with him) that when a husband takes an oath concerning his wife, he is to be made to stand at the completion of four months. It will be said to him: Either take her back or divorce her, and he will be compelled to do so.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الإيلاء / 15217