1)
How did his slave trick him?
1.
Radak: I told him to saddle the donkey for me. He left without my knowledge!
2)
Why did he say "Ki Pise'ach Avdecha"?
1.
Rashi: I cannot walk.
3)
Why does it say "Aleha" (feminine)?
1.
Radak: It was a female. "Chamor" includes male and female.
