Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v1.c6.10

v1.c6.10

Another kind of assumption which has been made about the motion of planets is that their eastward motions in their orbits are equal. But the distances of planets from the earth being unequal, the orbits of farther planets are wider than those of the nearer ones; and that is the reason why we notice difference in their eastward motions. The moon being nearest to the earth has the swiftest motion and Saturn being the farthest of all planets, its motion is the slowest. The Pañca-Siddhāntikā says :—