…The Lord diminished the duration of life of the opposite party by His merciful glance. It is said that all the fighters who assembled on the Battlefield of Kurukṣetra attained salvation by personally seeing the Lord at the time of death. Therefore, His diminishing the duration of life of Arjuna’s enemy does not mean that He was partial to the cause of Arjuna. Factually He was merciful to the opposite party because they would not have attained salvation by dying at home in the ordinary course of life. Here was a chance to see the Lord at the time of death and thus attain salvation from material life. Therefore, the Lord is all good, and whatever He does is for everyone’s good.
By His Divine Grace A.C. Bhaktivedanta Swami Prabhupada
Canto 1, Chapter 9, Text 35
The Passing Away of Bhismadeva in the Presence of Lord Krsna
sapadi sakhi-vaco niśamya madhye
nija-parayor balayo rathaṁ niveśya
sthitavati para-sainikāyur akṣṇā
hṛtavati pārtha-sakhe ratir mamāstu
sapadi—on the battlefield; sakhi-vacaḥ—command of the friend; niśamya—after hearing; madhye—in the midst; nija—His own; parayoḥ—and the opposite party; balayoḥ—strength; ratham—chariot; niveśya—having entered; sthitavati—while staying there; para-sainika—of the soldiers on the opposite side; āyuḥ—duration of life; akṣṇā—by looking over; hṛtavati—act of diminishing; pārtha—of Arjuna, son of Pṛthā (Kuntī); sakhe—unto the friend; ratiḥ—intimate relation; mama—my; astu—let there be.
In obedience to the command of His friend, Lord Śrī Kṛṣṇa entered the arena of the Battlefield of Kurukṣetra between the soldiers of Arjuna and Duryodhana, and while there He shortened the life spans of the opposite party by His merciful glance. This was done simply by His looking at the enemy. Let my mind be fixed upon that Kṛṣṇa.
In the Bhagavad-gītā (1.21-25) Arjuna ordered the infallible Lord Śrī Kṛṣṇa to place his chariot between the phalanxes of the soldiers. He asked Him to stay there until he had finished observing the enemies he had to face in the battle. When the Lord was so asked, He at once did so, just like an order carrier. And the Lord pointed out all the important men on the opposite side, saying, “Here is Bhīṣma, here is Droṇa,” and so on. The Lord, being the supreme living being, is never the order supplier or order carrier of anyone, whoever he may be. But out of His causeless mercy and affection for His pure devotees, sometimes He carries out the order of the devotee like an awaiting servant. By executing the order of a devotee, the Lord becomes pleased, as a father is pleased to carry out the order of his small child. This is possible only out of pure transcendental love between the Lord and His devotees, and Bhīṣmadeva was quite aware of this fact. He therefore addressed the Lord as the friend of Arjuna.