Kautilya's Arthashastra 14.3.59

14.3.59

dvigoyuktaṃ goyānam āhṛtaṃ bhavati //

Having fasted for four nights, one should on the fourteenth day of the dark half of the month get a figure of a bull prepared from the bone of a man, and worship it, repeating the above mantra. Then a cart drawn by two bulls will be brought before the worshipper who can (mount it and) drive in the sky and tell all that is connected with the sun and other planets of the sky.