Sita\’s two sons, Lava and Kusha, were then bom in the hermitage of the saint. The young ones were brought up and given all the required education with the greatest care. The sage is said to have taught his poem to them. Thus the sage himself is one of the characters of Ramayana.
References :
1. Kohli, Surindar Singh, Dictionary of Mythological References in Guru Granth Sahib, 1993