1)
What is the meaning of "Lo Yumsu Avos Al Banim
1.
Radak: It is like the verse concludes - one dies only for his own sin.
2.
Radak citing Sanhedrin 27b, Targum Onkelos (Devarim 24;16): This disqualifies testimony of relatives (one may not die via his relative's testimony). Malbim - they explained so because the end of the verse is superfluous.