Rashi on Nahum
they shall clatter Heb. יִשְׁתַּקְשְׁקוּן. Jonathan renders: The sound of the clattering of their weapons is heard. And that is from the expression (Joel 2:24) “And the vats shall roar (וְהֵשִׁיקוּ),” and (Isa. 33:4) “Like the roaring (כְּמַשַק) of the cisterns.” It is an expression of making a sound heard.
Rashi on Nahum
they shatter—They shatter their listeners like these lightnings, which agitate the creatures. So did Jonathan render it.