In plain words
Vasiṣṭha said, “Rāmo vigrahavān dharmaḥ.” Dharma itself took on the form of Rāma. We must follow Dharma. What is that Dharma? The principle that belongs to the heart is itself Dharma. We must not go the way the mind fancies.
She who has no delusion of the body: ‘Vaidehī’
To Rāma, the embodiment of Dharma, Sītā came as his companion. Where was Sītā born? She was born in the womb of the earth. While Janaka was ploughing the ground for a yajña, a box came to light from that womb of the earth. When he opened it and looked, there was a baby inside. Thinking, ‘This is a gift of grace to me from God’, Janaka brought the baby to his home, named her ‘Sītā’ and brought her up with the fondest care. Because Sītā was the daughter of Videha's king, she also came to be called ‘Vaidehī’. ‘Vaidehī’ means one who has no delusion of the body. This is a very important name.
The breaking of Śiva's bow
In Janaka's house there was a box. In it lay a great bow of Śiva. One day, while Vaidehī and some other children were playing together with a ball, the ball went under that box. No one could move the box aside. Sītā went, moved it aside with her left hand and took the ball out. Janaka, who saw that sight, resolved that very day to proclaim Sītā's strength and ability to the world. Later he undertook a yajña and announced that he would give Sītā in marriage to whoever could string the bow of Śiva. “The daughter of King Janaka is very great. To become son-in-law to one as great as King Janaka is great good fortune,” thought the kings of all the lands, and they came there. One after another they came in turn and tried to lift the bow of Śiva. But no one could do it. Rāma and Lakṣmaṇa, who had come with Viśvāmitra, were also in that assembly. At Viśvāmitra's bidding Rāma went forward.