niṣedha karite nāre - unable to prohibit Lord Rāmacandra; yāte - because; choṭa bhāi - younger brother; mauna dhari' - becoming silent; rahe - remains; lakṣmaṇa - Lakṣmaṇa; mane - in the mind; duḥkha - unhappiness; pāi' - getting.

As a younger brother He could not stop Lord Rāma from His resolution, and so He remained silent, although unhappy in His mind.