In plain words
The one born of Kausalyā's pāyasa is Lakṣmaṇa. He is a part of Rāma. The one born of Kaikeyī's pāyasa is Śatrughna. He is a part of Bharata. So lay Lakṣmaṇa down beside Rāma and Śatrughna beside Bharata. They will sleep without a care,” he said. As soon as Sumitrā laid them down that way, they stopped crying and slept happily. Afterwards both woke up playing. Seeing this, Sumitrā was overjoyed. She dedicated Lakṣmaṇa to the service of Rāma and Śatrughna to the service of Bharata. ‘These children were born in my womb only to serve those two. It is my good fortune to give the world such servants devoted to service’, she thought. No one knows for what reason, for what work, where, when and what God will bring about. As they grew up, Lakṣmaṇa followed Rāma and Śatrughna followed Bharata like a shadow. Lakṣmaṇa and Śatrughna were men of great strength. Without them there would be no Rāmāyaṇa at all. We think, ‘They were born to this one, they were born to that one’, but that is not right. These four are parts of one and the same substance, not separate. To Kausalyā, Sumitrā and Kaikeyī came such a sacred fortune.
Once Bharata came running, sat in Kausalyā's lap and was crying. “Bharata! Why are you crying?” asked Kausalyā. Bharata: “Mother! In the ball game my brother keeps losing on purpose, so that I should win. That is why I am sad,” he said. What closeness between them! See! In this way the four brothers lived in deep affection for one another and went on experiencing joy. Wherever Rāma went, Lakṣmaṇa had to be at his side. Wherever Bharata went, Śatrughna had to be with him as his companion. No one but Lakṣmaṇa knew the true nature of Rāma. In the same way, Śatrughna alone could understand the true nature of Bharata. Who is Śatrughna? He who destroys enemies is Śatrughna. There is no use in sitting and describing the virtues of these four brothers without following their ideals.