15 They cried unto them, Depart ye; it is unclean; depart, depart, touch not: when they fled away and wandered, they said among the heathen, They shall no more sojourn there.
[AD 1274] Thomas Aquinas on Lamentations 4:15
Here is considered the derision of captured citizens by their enemies. So, first the profanation of holy things was blamed on these enemies. As said: "Away! Unclean!' men cried out to them." Namely, enemies cried out against the Jews, as ones unclean from their own places.

Then: "Away! Away! Touch not!" That is, you Jews, unclean as to holy things. As Leviticus 21:16-17 states: "And the Lord said to Moses, 'Say to Aaron, none of your descendants throughout their generations who has a blemish may approach to offer the bread of his God.'"

Secondly, was blamed on the Jews the indignation of their Lord God, insofar as to a destruction of divine aid.

So Verse 15 continues: "so they became fugitives and wanderers." Namely, as enemies blaming each other (as Jews); and by chiding and grieving among themselves.

As Verse 15 concludes: "Men said among the nations, 'They shall stay with us no longer'." That is, as if, God depended on the Jews. As Psalm 71 (70):ll states: "And say, 'God has forsaken him; pursue and seize him; for there is none to deliver him.'"