Musannaf Ibn Abi Shayba 19:965

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Muhammad ibn Abd Allah ibn ‘Ulatha: A man accused another man of adultery (qadhf), so he brought him before Umar ibn Abd al-Aziz. The accuser claimed that his evidence for what he said was in Armenia, meaning it was absent. Umar ibn Abd al-Aziz said: "The prescribed punishment (hadd) is not delayed. However, if you bring evidence, I will accept their testimony."