Which of these two came earlier, which came later? How did they come to birth? Who, O Seers, can discern it? They contain within them all that has a name, while days and nights revolve as on a wheel. You two, though motionless and footless, nurture a varied offspring having feet and movement. Like parents clasping children to their bosoms, O Heaven and Earth, deliver us from evil! These twin maidens (day and night), like two friendly sisters nestled close together, rest in their parents' bosom and kiss together the center of the world. O Heaven and Earth, deliver us from evil!

(The Rig Veda)