Charles H. Spurgeon on Psalms 78:63

The fire consumed their young men. Fire here may be regarded as an image of destructive war, as in Nu 21:28. "For there is a fire gone out of Heshbon, a flame from the city of Sihon: it hath consumed Ar of Moab, "etc. Albert Barnes.

Verse 63 (first clause). When religion is overthrown among God's people, let not the commonwealth think to stand: when God gave his glory unto the enemies' hand, "He gave his people over also unto the sword, and the fire consumed their young men." David Dickson.