Musannaf Ibn Abi Shayba 21:350

Yazid ibn Harun narrated to us, Muhammad ibn ‘Amr informed us, from Muhammad ibn Ibrahim, who said: ‘Ubadah ibn al-Samit said: "For me to be among a people who remember Allah from the time they pray the morning prayer until the sun rises is more beloved to me than for me to be upon the backs of horses, striving in the way of Allah until the sun rises. And for me to be among a people who remember [Allah] from the time they pray the afternoon prayer until the sun sets is more beloved to me than for me to be upon the backs of horses, striving in the way of Allah until the sun sets."