It was narrated from Salamah bin Sakhr Al-Bayedi that:
the Prophet ﷺ said concerning a man who declared Zihar upon his wife having intercourse with her before compensation: "Let him offer one expiation."

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ سَعِيدٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ إِدْرِيسَ، عَنْ مُحَمَّدِ بْنِ إِسْحَاقَ، عَنْ مُحَمَّدِ بْنِ عَمْرِو بْنِ عَطَاءٍ، عَنْ سُلَيْمَانَ بْنِ يَسَارٍ، عَنْ سَلَمَةَ بْنِ صَخْرٍ الْبَيَاضِيِّ، عَنِ النَّبِيِّ ﷺ فِي الْمُظَاهِرِ يُوَاقِعُ قَبْلَ أَنْ يُكَفِّرَ قَالَ " كَفَّارَةٌ وَاحِدَةٌ " .