Bearing in mind Pasuk 24 ("Ayin Tachas Ayin"), which teaches us the obligation to pay for injuries that one causes, why does the Torah see fit to insert this Parshah?
Rashi and Targum Yonasan: To teach us that, besides paying for the actual injury, one is also Chayav to pay for work-loss and medical fees 1 .
"Shivto Yiten v'Rapo Yerapei". He is also Chayav to pay for the pain and the embarrassment (Targum Yonasan), which Rashi omits, because we learn them from another source (Sifsei Chachamim).
What are the connotations of "ve'Nafal le'Mishkav"?
Rashi: It means that the victim has been incapacitated and is unable to continue working in his regular occupation.
What is an "Egrof"?
Ramban and Targum Yonasan: It means a fist.
Ramban (citing Ibn Ezra, Redak and Targum Onkelos: A clod of earth (which is also relatively soft).
What is the significance of "be'Even Oh be'Egrof"? Why does the Torah mentions them both?
Ramban #1: The Torah is coming to teach us that although the former is hard and prone to kill whereas the latter (a fist) is soft and does not usually kill, both require the assessment mentioned in the next Pasuk. 1
And we neither assume outright that the former killed the victim, nor that the latter did not. If the victim subsequently dies, the accused is sentenced to death, and if he survives, then he has to pay (Ramban). And the Torah deliberately avoids mentioning a sword, which is always capable of killing, and does not need any assessment (Ramban citing Sanhedrin, 76b).
To preclude where the stone is mixed up with other stones and cannot be identified (Ibid).
Thereby obligating the stroke of the fist to be assessed - as to whether it was capable of killing the victim (Ramban).