Lamenting thus and even welcoming death itself, Arjuna said: If the sons etc. If they should slay me unresisting meaning sitting quietly, them that death would be extremely beneficial for me, since it would stop me from contracting the reaction of committing this heinous sin.

Madhvacarya has no commentary so we present Baladeva Vidyabhusana's.

If it is asked: O Arjuna, even though you refrain yourself from killing your relatives, it is sure that Bhishma and the Kauravas will certainly kill you without hesitation as they are eager to engage in this war. So what will you do under these circumstances? To answer this Arjuna is speaking this verse beginning yadi mam apratikaram. Being not vengeful is my atonement for my resolve to slay them. Ksemataram means much better, since the atonement of death will wash away all sins. Bhishma and the others fighting on the Kaurava side will not be able be able to escape the result of that sin. This is the internal mood that Arjuna is feeling.

It may be put forth that although Arjuna disregarding ksatriya ethics might refrain from battle out of deluded compassion for friends and kinsman; but as far as the enemy is concerned they will not refrain themselves from battle; but are determined to fight for dominion of the kingdom. Being fully intent on victory the sons of Dhritarastra may slay you even if you do not fight. Then what is the use of not fighting? In answer to this Arjuna states that even if the sons of Dhritarastra being devoid of wisdom and obsessed by greed would slay him unarmed and unresisting, this would still be more preferable than perpetuating sin by slaying friends and kinsman and permanently going to hell as a result. What Arjuna is practically saying is that if he refrains from fighting then at the deaths of his physical body there would be no feelings of guilt or repentance from committing such a sin.