After his father Kim Chun-chu, who had not ascended the throne as King Muyeol yet, established a close relationship between Tang China and Silla and returned to the country, Kim Beopmin visited Tang in June 650 in order to report the victory of a local war against Baekje in 649 and present a great peace poem of five-word verses written by Queen Jindeok, admiring the prestige of the Tang Dynasty.
武烈王として即位する前の父・金春秋が唐と新羅との緊密な関係を築いて帰国した後、649年の百済との局地戦の戦勝報告と、真徳女王が唐の威光を称えて作った五言太平頌を献上することとを任務として、金法敏は650年6月に唐を訪れた。