Musannaf Ibn Abi Shayba 35:449

Muhammad ibn Fudayl narrated to us, from Yazid, from Abd al-Rahman ibn Abi Layla, he said: So-and-so ibn so-and-so narrated to me that the Prophet, may Allah bless him and grant him peace, said: "Indeed, the solar eclipse is a sign from the signs of Allah. So when you see that, then hasten to the prayer."