Commentary for Deuteronomy 32:33

חמת תנינים יינם THEIR WINE IS THE POISON OF DRAGONS — Understand this as the Targum does: הא כמרת תניניא כס פורענותהון which means: Behold, like the gall of serpents is the cup of the drink of their punishment.

חמת תנינים יינם, their wine is the venom of asps; among the clusters mentioned in verse 32 there are also poisonous grapes, hidden and unidentifiable among the grapes. This disaster awaits them as a manifestation of the attribute of Justice they have richly deserved. Until they actually are extracting the juice from these grapes [this is all hyperbole, of course, Ed.] G’d did not convert His threat of retribution into something actual. Compare Isaiah 63,3, G’d saying that He alone squeezed out these grapes by treading on them.

חמת תנינים, they should by rights have been made to drink the venom of asps had it not been for the desecration of G’d’s holy name that would have resulted from this, for the nations would have said: “we have accomplished this.”