In plain words
You will be able to guard the yāga with zest,” he said. Setting out from there, the three reached Siddhāśrama. Viśvāmitra began the yajña. Repeating the mantras he had taught them, Rāma and Lakṣmaṇa guarded the yajña night and day. The rākṣasas, making terrible noises, tried in many ways to obstruct the yajña. Rāma and Lakṣmaṇa faced them with a smile. At the guru's command Rāma slew Tāṭaki; he made Mārīca fall some thousands of yojanas away; he put an end to Subāhu. In this way, under the protection of Rāma and Lakṣmaṇa, Viśvāmitra's yajña was completed without hindrance. Viśvāmitra was overjoyed, and blessed the two brothers with great love.
The breaking of Śiva's bow by Rāma
Meanwhile a message came from the city of Mithilā. Janaka had sent a letter inviting Viśvāmitra to grace the yāga he had undertaken. Viśvāmitra, to Rāma and Lakṣmaṇa: “Dear boys! An invitation has come to us from Mithilā. You too must surely come to see the yajña King Janaka is performing,” he said. Then Rāma: “Revered guru! Our father sent us to guard your yajña; he did not tell us to go to the city of Mithilā and take part in the yajña King Janaka is performing, did he!” he said. At once Viśvāmitra: “My son! What was your father's command? He ordered you to do as the sage Viśvāmitra says, did he not! So ask no more questions and follow me,” he said. What could Rāma and Lakṣmaṇa do! Without a word in reply they set out for Mithilā with Viśvāmitra.
The people of Mithilā saw Rāma and Lakṣmaṇa: “Who are these princes? How handsome they are! They look like great heroes, full of radiance. Is King Janaka going to give his daughters to them in marriage?” they kept saying among themselves.