Musnad Ahmad 27:1097

Mus'ab ibn Salam narrated to us, Muhammad ibn Suqah narrated to us, I heard Abu Ja'far say: When Abdullah ibn Umar would hear something from the Prophet of Allah, may Allah bless him and grant him peace, or witness an event with him, he would neither fall short of it nor exceed it. He said: While he was sitting and Ubayd ibn Umayr was telling stories to the people of Makkah, Ubayd ibn Umayr said: "The likeness of the hypocrite is like the sheep between two flocks; if it approaches this flock, it butts it, and if it approaches that one, it butts it." Abdullah ibn Umar said: "It is not like that." Ubayd ibn Umayr became angry. Abdullah ibn Safwan was in the gathering and said: "O Abu Abd al-Rahman, how did he say it, may Allah have mercy on you?" He said: He said: "The likeness of the hypocrite is like the sheep between two pens; if it approaches this pen, it butts it, and if it approaches that pen, it butts it." He said to him: "May Allah have mercy on you, they are the same." He said: "This is how I heard it, this is how I heard it."