Psalm 61:3

And a strong tower from the enemy. As in a fort impregnable, David had dwelt, because surrounded by omnipotence. Sweet is it beyond expression to remember the lovingkindnesses of the Lord in our former days, for he is unchangeable, and therefore will continue to guard us from all evil.

Verse 3. A shelter from the rain of trouble, the storm of persecution, the floods of Satanic temptation, the heat of divine wrath, the blast of death. The ark, Lot's mountain, the blood stained door in Egypt, the city of refuge, the cave Adullam. A strong tower: lasting in itself, impregnable against foes, secure for the occupant.