 The ten Sikh Satgurus talk about the inner sound and inner light a lot in their scriptures.The first Sikh Satguru was Sri Guru Nanak Dev Ji, but people believe his master was Waheguru.However, according to history during the True merchandise(ਸਚਾ ਸਉਦਾ) Guru Nanak Dev Ji, interacted with some living masters and term Waheguru is a combination of two words that is Wahh and Guru.