Parashas Masei · Passuk 35:20 · TT note 1
Chabad.org — English translation + Rashi
Torah Temimah points to Sifrei (TT note on “וְאִם בְּשִׂנְאָה יֶהְדָּפֶנּוּ”).
English: “And if in hatred he pushes him” — I have only [liability for] striking with an iron implement, a hand-stone or a wooden implement; from where [do we know] that if he pushed him from a rooftop and he fell and died he is liable? Scripture says “and if in hatred he pushes him” — in any case.
Expansion of liability from instrument-strikes to intentional pushing from a height.
An intentional push from a roof that causes death is capital murder, just as striking with iron, stone or wood.