New Defender's Study Bible Notes
103:11 heaven is high. The Lord, in picturing His infinite mercy, uses the infinite height of the heavens as the appropriate simile, thus predating the most modern concepts of observational astronomy.
103:12 east is from the west. Here is a second figure applied to the limitless scope of God’s forgiving grace. One can travel east (or west) forever without coming to its end. This perfectly fits the idea of a global earth.