Bhagavad-Gita: Chapter 11, Verse 34

Rudra Vaisnava Sampradaya:

Visnuswami

Sridhara Swami's Commentary

Lord Krishna is annihilating any doubts that may linger in Arjuna regarding chapter two verse five and six when he questioned fighting superiors with the word gariyo meaning is it beneficial. In the same way Arjuna by the code of royal ksatriyas or warriors should annihilate all opponents on the battlefield and not be distressed or afraid of any retribution as they have already been slain by Lord Krishna specifically naming Drona, Bhishma, Jayadratha and Karna.

Brahma Vaisnava Sampradaya:

Madhvacarya

Madhvacarya's Commentary

Whoever severs Jayadratha's head from his body causing it to fall on the ground will instantly have their own head burst into pieces. Thus one who slays him is also in the mouth of death and that is why his name is specially mentioned as this was a boon given to him by his father. Karna has special power given to him by a weapon from Indra that will slay any one it strikes but only can be launched once, Bhishma has the boon that he will die only at the time he so desires and Drona cannot be defeated by any weapon receiving the boon of knowledge of every weapon and how to neutralise them from the avatar or incarnation Parasurama Himself. But by the express desire of the Supreme Lord Krishna they all will certainly perish on the battlefield and Arjuna and the Pandavas will be victorious.

Sri Vaisnava Sampradaya:

Ramanuja

Ramanuja's Commentary

Lord Krishna confirms that Drona, Bhishma, Karna along with innumerable warriors have already been slain by Him so Arjuna should not hesitate or feel remorse for slaying his enemies be they superiors, preceptors, relatives or friends in battle for they fighting for the unrighteous Duryodhana have already been marked for destruction by Lord Krishna. In this verse Arjuna is assured of victory over his enemies on the battlefield and he should not feel even the slightest doubt about this or think he is performing sins by slaying his enemies.

Kumara Vaisnava Sampradaya:

Nimbaditya

Kesava Kasmiri's Commentary

Arjuna may have doubt reflecting that Drona received the divine science of weapons by mantra from avatara or incarnation Parasurama Himself. Also he is hesitant to slay Drona who had taught him so well the science of archery making him the greatest archer in the world. Bhisma has received the boon that he can die at the time of his choosing and educated by Brihaspati the guru of the demigods, he was invincible. Jayadratha has the boon from his father that whoever takes his head off at the neck with any weapon will have their own head burst into pieces. Karna the son of the Surya the sungod has received a boon from Indra in the form of a weapon that will slay whoever he launches it at. Also there are other warriors such as Kripacarya and Asvatthama who are undefeatable in battle. Arjuna is certainly not doubting the words of Lord Krishna but with such a powerful array of mighty warriors against him, he was wondering how he will be able to defeat them all.