’Twas feathered with the rushing wind; The glowing sun and fire combined To the keen point their splendour lent; The shaft, ethereal element, By Meru’s hill and Mandar, pride Of mountains, had its weight supplied.

In plain words: The arrow is described as made of great powers: the wind gave it feathers, the sun and fire gave its point its blaze, and the great mountains Meru and Mandara gave it weight.