In plain words
My babies keep crying all the time! What can the reason be?” she asked. He looked into it with his divine sight: “Mother! That day, when the kite snatched away your bowl of pāyasa, Kausalyā and Kaikeyī each gave you half of their pāyasa, did they not! The one born of the pāyasa Kausalyā gave is Lakṣmaṇa. So he is a portion of Rāma. In the same way, the one born of the pāyasa Kaikeyī gave is Śatrughna. He is a portion of Bharata. So take Lakṣmaṇa and lay him in Rāma's cradle. In the same way, lay Śatrughna beside Bharata,” he advised. Sumitrā did as he said. From that moment Lakṣmaṇa and Śatrughna stopped crying, fed on time, slept on time and passed their days happily.
Lakṣmaṇa always followed in Rāmacandra's footsteps. In the same way, Śatrughna was always at Bharata's side. Sumitrā understood that Lakṣmaṇa was a portion of Rāma and Śatrughna a portion of Bharata. She said to her two sisters, “My dears! The sons born to you may rule the kingdom. But I have no such desires. If my two sons spend their days happily in your sons' service, that is enough.” Since Lakṣmaṇa was a portion of Rāma, he should always spend his days happily in Rāma's service alone: so Sumitrā wished. In the same way, she wished that Śatrughna should serve Bharata. Daśaratha too came to know this mystery, this secret. Be that as it may, he was glad that the three wives were passing their days happily with the children.
Guarding Viśvāmitra's yāga
Hardship and happiness keep following one upon the other, do they not! While Daśaratha's days were passing happily, one day Viśvāmitra came: ‘Great king! I have come hoping for a favour from you’, he said. Without a second thought, Daśaratha promised that he would surely do whatever was wanted.