God is known in her palaces - The word rendered “palaces” here means properly a fortress, castle, or palace, so called from its height, from a verb, ארם 'âram, meaning to elevate, to lift up. It may be applied to any fortified place, and would be particularly applicable to a royal residence, as a castle or stronghold. The word “known” here means that it was well understood, or that the point had been fully tested and determined that God had chosen those abodes as his special residence - as the place where he might be found.
For a refuge - See the notes at Psalms 46:1. That is, there was safety or security in the God who had chosen Jerusalem as his special abode.