Albert Barnes Commentary Jeremiah 51:50

"Ye that have escaped the sword, go ye, stand not still; remember Jehovah from afar, and let Jerusalem come into your mind." — Jeremiah 51:50 (ASV)

Afar off - Or, from afar, from Chaldea, far away from Yahweh’s dwelling in Jerusalem. The verse is a renewed entreaty to the Jews to leave Babylon and journey homewards, as soon as Cyrus grants them permission.