Vanara Dharmaka states-
Sapta-ṣaśṭir hatān koti vānarānām tarasvinām Ya sanjīvana yāmāsa tam vande mārutātmajam.
Meaning- I bow in reverence to that great Vanara hero, Hanuman, who brought the Sanjeevani herb and brought back to life 67 crore strong Vanaras who were lying dead in the battlefield.
Aha! Each great Vānara warrior, through his hymn, showers limitless praise upon Hanuman. It can be said that the entire life story of Hanuman is being brought out through these compositions.
67 crore vanaras could be revived just by the smell of the Sanjivani herb! The next logical question would be-‘why couldn’t the smell of this herb bring back to life the dead demons as well?’ It is true that the demons could not be revived. This was because Ravana had given stringent instructions that the body of any demon who dies in the battle should be disposed off into the ocean instantly. The number of dead demons should not be countable. He did not want Rama to know how many demons had died in battle. The bodies that were being thrown into the ocean instantly became the food for the animals inhabiting the ocean. How then could they be revived?
During the war, Indrajit, the son of Ravana, began to fearfully strike Sugriva’s army with fierce weapons. He was invincible in war. Using the powerful weapon Brahmastra, he wiped out crores of vanaras. Rama who was watching this, called Lakshmana and said-‘Indrajit is waging a ferocious war. Due to the boon received from Brahma, he has made himself invisible and is striking our army with his Brahmastra. We cannot attack him when he is invisible. Therefore, let us stand here in the battlefield in a composed manner and allow the weapons to pierce us. For the time being, give up your anger as well as your desire to fight. Let us pretend to have fallen in a swoon due to the effect of the Brahmastra. Seeing us unconscious, Indrajit will be under the illusion that he is victorious. He will make himself visible and will leave the battlefield”. This was Rama’s strategy.
Our ancient Puranas contain innumerable stories wherein Brahma gives away very powerful boons to the demons. It also appears to us that such boons eventually land Brahma in trouble. However, it should be noted that all these happen as per God’s will. The events are pre-destined. Brahma has to give away these seemingly invincible boons to the demons, the Lord has to incarnate as a result of these boons and through that incarnation the Lord has to destroy these demons. All these three steps are inter-twined. Indrajit likewise had the boon from Brahma due to which he could become invisible. Using this boon, he began to strike the helpless vanaras from various directions.
Rama and Lakshmana fell into a swoon. Whether this was the effect of the Brahmastra or whether they did this due to their will, has been retained as a secret in Ramayana. This is also a debated topic. If it is said that Rama and Lakshmaṇa fell into a swoon due to the effect of the Brahmastra, then people question- how could the brothers, who were incarnation of the supreme, be affected by a Brahmastra? If it is argued that they did not allow the Brahmastra to affect them, then the question that props up is – how can the all-powerful Brahmastra be rendered ineffective? Now, from the conversation between the two brothers we clearly understand that they pretended to be in a swoon. Indrajit’s response was exactly as predicted by Rama, and in great elation Indrajit returned back home.
Due to the effect of the Brahmastra, other prominent Vānara warriors such as Angada, Jambavanta, Neela and Sugriva were rendered motionless even though they were alive.