Sulayman bin Yasar (may Allah have mercy on him) says: I found more than ten Companions (may Allah be pleased with them) of the Prophet (peace and blessings be upon him) who used to say that the one who makes ila' (an oath to abstain from his wife) will be made to stand before the judge.
Imam al-Shafi'i (may Allah have mercy on him) says: The least that "bid'ata 'ashar" (ten-odd) can mean is thirteen, and they say: they were from the Ansar.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الإيلاء / 15207