Musnad Ahmad 937:117

Waki' narrated to us, al-A'mash narrated to us, from Ibrahim al-Taymi, from his father, from Abu Dharr, who said: I asked the Prophet, peace and blessings of Allah be upon him, about the saying of Allah the Exalted: {And the sun runs to a resting place for it} [Ya-Sin: 38]. He said: "Its resting place is beneath the Throne."