Rashi: A full, special evil above all evils - Churban ha'Bayis.

Radak: There is no evil like this ¹ , like it says above (5:9) "v'Asisi Vach Es Asher Lo Asisi v'Es Asher Lo E'eseh."

Radak: It seems that Yonason's text was Ra'ah Achar Ra'ah; he translated 'evil after evil.'

Malbim: This evil is unlike all evils that came until now. Until now, the decree was not sealed. Now that it was sealed, there are three changes. (a) Until now, the evil did not come at once. First they were stricken monetarily, and afterwards afflicted [bodily]. The Master of mercy does not initially strike mortally - perhaps they will repent. Now one evil will come - bodily punishment will come immediately. (b) Until now, the evil came for a good purpose - so they will repent. Now it is coming for the sake of evil. (c) Until now, evil did not come immediately - first they were warned, and He waited - perhaps they will repent. Now it will come immediately.

Rashi (5, 7, and Bereishis 29:6): The accent is on the Aleph (the last syllable); it is present tense. When the accent is on the Beis, it is past tense.