“The gods arose
And took their horses, and set forth to ride
O’er the bridge Bifröst, where is Heimdall’s watch,
To the ash Igdrasil, and Ida’s plain.
Thor came on foot, the rest on horseback rode.”
Balder Dead (Matthew Arnold).
Of all the gods only Thor, the god of thunder, never passed over the bridge, for they feared that his heavy tread or the heat of his lightnings would destroy it. The gods’ watchman, Heimdall, kept guard there night and day. He was armed with a very trenchant sword, and carried a trumpet called Giallar-horn, upon which he generally blew a soft note to announce the coming or going of the gods, but upon which he would blow a terrible blast when Ragnarok should come, and the frost giants and Surtr threatened to destroy the world.
“Surt from the south comes
With flickering flame;
Shines from his sword