Yuddhakānda - Canto 41

Śrī Rāma is not very pleased with the daring act of Sugrīva inasmuch as he had seen evil portents. Warning him against such action on the ground of his being a sovereign, and commanding the monkey generals to besiege all the four gates of Lankā, he dispatches Angada to expostulate with Rāvana and bring him to reason. Angada tries his best to bring him round, but in vain, and returns unsuccessful to the presence of Śrī Rāma after threatening the ogres.