Psalms 46:2

Therefore will we not fear, though earth should change,

And the mountains be moved into the heart of the seas.

Cp. Horace's description of the dauntlessness of the just man (Odesiii. 3. 7),

Si fractus illabatur orbis,

Impavidum ferient ruinae.

The words are to be understood literally (Isaiah 54:10), and not metaphorically, as "a vivid sketch of utter confusion, dashed in with three or four bold strokes, an impossible case supposed in order to bring out the unshaken calm of those who have God for ark in such a deluge" (Maclaren). At the same time they suggest the thought of the upheaval and commotion of the nations, and (Psalms 46:3) the flood of invasion beating against mount Zion and threatening to overwhelm it. Cp. Psalms 46:6; Isaiah 17:12-13.