Abu Dawud Book 18, Hadith Number 3592.

Narated By Khuraym Ibn Fatik : The Apostle of Allah (PBUH) offered the morning prayer. When he finished it, he stood up and said three times: False witness has been made equivalent to attributing a partner to Allah. He then recited: “So avoid the abomination of idols and avoid speaking falsehood as people pure of faith to Allah, not associating anything with Him.