Durbasa, the king Furu and the sage Angarai (Angiras) sang the Praises of Guru Nanak Dev. (Swayye Mahle Pahle Ke, p. 1390) The sage Angiras is said to be the author of many hymns of Rig Veda. He was one of the Sapt-rishis and one of the ten Prajapatis.