I performed zihar against my wife, then I had relations with her before making expiation. So I asked the Prophet ﷺ, and he instructed me to make the expiation.
قال حدثنا يزيد بن هارون أنبأنا محمد بن إسحاق عن محمد بن عمرو بن عطاء عن سليمان بن يسار
تظاهرت من امرأتي ثم وقعت بها قبل أن أكفر فسألت النبي ﷺ فأفتاني بالكفارة
Its isnad is sahih. Its narrators are well known. Ibn Ishaq narrated with "an" without specifying direct transmission, but Tirmidhi graded it hasan, as in the one following it.