>Where did it come from?

unknown; may be a cognate of light. but I can tell you that it's been used mostly poetically; to wit:

1596 Spenser F.Q. v. vi. 40 As when the flashing Levin haps to light Vppon two stubborne oakes. 1647 H. More Song of Soul ii. i. i. xxii, Swift as the levin from the sneezing skie. 1808 Scott Marm. i. xxiii, The Mount, where Israel heard the law, 'Mid thunder-dint, and flashing levin, And shadows, mists, and darkness, given. 1851 Longfellow Gold. Leg. v. At Sea, See! from its summit the lurid levin Flashes downward. 1855 Singleton Virgil I. 348, I would that.. the almighty sire Would hurl me with his leven to the shades. 1880 Swinburne Songs Springtides, Gard. Cymodoce 90 The leaping of the lamping levin afar.