Rashi on Genesis 11:7/רש"י על בראשית י״א:ז׳

1הבה נרדה COME, LET US GO DOWN — He took counsel with His Judicial Court because of His exceeding meekness (Sanhedrin 38b)

2הבה COME — measure for measure: they had said “Come, let us build“; He meted out to them correspondingly saying. “Come let us go down” (Midrash Tanchuma, Noach 18)

3ונבלה means AND LET US CONFOUND The נ is the plural prefix, and the ה at the end is additional to the root as the ה in ונרדה.

4ולא ישמעו — THEY MAY NOT UNDERSTAND — One asks for a brick and the other brings him lime: the former therefore attacks him and splits open his brains.