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." (ID)
English reference (ID): Vol. 3, Book 10, Hadith 2464 (ID)
Arabic reference (ID): Book 10, Hadith 2142 (ID)