Musannaf Ibn Abi Shayba 33:378

Waki’ narrated to us, from Mis’ar, from Ibrahim al-Saksaki, who said: Our companions narrated to us, from Abu al-Darda’, who said: If you wish, I will swear to you that the most beloved of the servants to Allah are those who love Allah and make Allah beloved to His servants. And those who observe the sun, the moon, the stars, and the shadows for the remembrance of Allah.