From Sahih Bukhari (Hadith 6832):
Narrated Zaid bin Khalid Al-Juhani:I heard the Prophet (ﷺ) ordering that an unmarried person guilty of illegal sexual intercourse be flogged one-hundred stripes and be exiled for one year. `Umar bin Al-Khattab also exiled such a person, and this tradition is still valid
Reference: Bukhari 6832