In plain words
They play. They sing. They rejoice. If you inquire who they are, the Veda itself has been setting out what they truly are. He who took Dharma itself as His form is Rāma. He Himself is the Yajur Veda. He who took refuge in the Name of Rāma, which is this Yajur Veda, and kept repeating it without ceasing in his word and in his work, is Lakṣmaṇa. He himself is the Ṛg Veda. The one who kept chanting the Name of Rāma itself as a song, and merged his life in that song, is Bharata. He himself is the Sāma Veda. Śatrughna, who subdued the inner and outer forces, bowed his head to the commands of these three and destroyed the enemies, is the Atharvaṇa Veda. So the Ṛg, Sāma, Yajur and Atharvaṇa Vedas are all playing in this house of Daśaratha in the forms of Rāma, Lakṣmaṇa, Bharata and Śatrughna. But who is this Daśaratha? He is not an emperor. The five organs of action and the five organs of knowledge: the chariot these ten senses come together in is this body. This is Daśaratha. The meaning is that in this body, the chariot of the ten senses, the boys who are the Ṛg, Yajur, Sāma and Atharvaṇa Vedas were born as Rāma, Lakṣmaṇa, Bharata and Śatrughna. They are known as those of the Solar line. Here, as for the sun: when we inquire in the outer, physical form, there is the sun and there is the moon. There is the earth. Where did this earth come from? It came from the sun. Where did this moon come from? It came from the earth. So the moon and the earth have come forth from the sun. They are only some parts of the sun. If you really inquire, if there were no sun at all, there would be no world at all. There would be no birth and death. There would be no form of any kind. That is why people have been worshipping the sun as the chief deity. They have believed the sun itself to be the God seen before their eyes. Parts of this sun are present in every man. Every man has come forth out of the sun's rays. The light in us is itself a ray of the sun. Since his light is in us, a part of him is in us too. Every man, being a part of the sun, belongs to the Solar line. If you ask who Rāma is, they said He is of the Solar line. So, in every man, the principle called Ātmārāma is joined with a part of the sun, and so it took shape as the Solar line. So Rāma does not mean only the son of King Daśaratha. All of you are embodiments of Rāma. This Solar line stands firm in all of you. Believe that part of the sun to be the Solar line, and just as Rāmacandra, king of the Solar line, destroyed the wicked and protected the good, so too destroy the bad thoughts, bad qualities and bad intentions in you, and strive to nourish good qualities and good conduct. This is the yajña every man must perform every moment.