Musnad Ahmad 937:134

Isma'il narrated to us, Ayyub narrated to us, from Abu al-'Aliyah al-Barra', who said: Ibn Ziyad delayed the prayer, so 'Abdullah ibn al-Samit came to me. I placed a chair for him and he sat upon it. I mentioned to him the action of Ibn Ziyad, so he bit his lip and struck my thigh, and said: "I asked Abu Dharr just as you asked me, and he struck my thigh just as I struck your thigh, and said: 'I asked the Messenger of Allah (peace and blessings of Allah be upon him) just as you asked me, and he struck my thigh just as I struck your thigh, and said: "Perform the prayer at its time. Then, if you catch them [praying], pray with them, and do not say: 'I have already prayed, so I will not pray.'"