Thou makest us a byword among heathen - The word rendered "by-word" - משׁל mâshâl - means properly a similitude or parable; then, a sententious saying, and apophthegm; then, a proverb; then, a song or verse, particularly a satirical song, or a song of derision. The idea here is, that they were made a proverb, or were referred to as a striking instance of the divine abandonment, or as something marked to which the nations might and did refer as an example of calamity, judgment, misfortune, failure; a warning to all. See Deuteronomy 28:37.
A shaking of the head among the people - An occasion for the shaking of the head, in derision and scorn. Compare the notes at Psalm 22:7.

Thou makest us a byword - We are evidently abandoned by thee, and are become so very miserable in consequence, that we are a proverb among the people: "See the Hebrews! see their misery and wretchedness! see how low the wrath of God has brought down an offending people!" And the worst curse that can be imprecated against a wicked nation is: "Mayest thou become as wretched as the Jews;" or as the old Psalter: Thou has seet us reprove til our neghburs: scornyng and hethyng til tha that er in our umgang. That es, gref, tourment that es of our neghburs, and that hethyng es noght sone gave or passand, that we suffer of tha, that er al aboute us. When men sais so byfal ye, als byfel him."

Thou makest us a byword among the Heathen,.... Among the Papists, as the Jews were among the Gentiles, Deuteronomy 28:37; calling them schismatics, heretics, fanatics, and what not?
a shaking of the head among the people; by way of indignation, scorn, and contempt; see Psalm 22:7.