SB 9.10.8

yaḥ satya-pāśa-parivīta-pitur nideśaṁ
 straiṇasya cāpi śirasā jagṛhe sabhāryaḥ
rājyaṁ śriyaṁ praṇayinaḥ suhṛdo nivāsaṁ
 tyaktvā yayau vanam asūn iva mukta-saṅgaḥ
Synonyms: 
yaḥ — Lord Rāmacandra who; satya-pāśa-parivīta-pituḥ — of His father, who was bound by the promise to his wife; nideśam — the order; straiṇasya — of the father who was very much attached to his wife; ca — also; api — indeed; śirasā — on His head; jagṛhe — accepted; sa-bhāryaḥ — with His wife; rājyam — the kingdom; śriyam — opulence; praṇayinaḥ — relatives; suhṛdaḥ — friends; nivāsam — residence; tyaktvā — giving up; yayau — went; vanam — to the forest; asūn — life; iva — like; mukta-saṅgaḥ — a liberated soul.
Translation: 
Carrying out the order of His father, who was bound by a promise to his wife, Lord Rāmacandra left behind His kingdom, opulence, friends, well-wishers, residence and everything else, just as a liberated soul gives up his life, and went to the forest with Sītā.
Purport: 

Mahārāja Daśaratha had three wives. One of them, Kaikeyī, served him very pleasingly, and he therefore wanted to give her a benediction. Kaikeyī, however, said that she would ask for the benediction when it was necessary. At the time of the coronation of Prince Rāmacandra, Kaikeyī requested her husband to enthrone her son Bharata and send Rāmacandra to the forest. Mahārāja Daśaratha, being bound by his promise, ordered Rāmacandra to go to the forest, according to the dictation of his beloved. And the Lord, as an obedient son, accepted the order immediately. He left everything without hesitation, just as a liberated soul or great yogī gives up his life without material attraction.