 Lukman Sardi , who played Dahlan , was also unaware of his character 's historical biography before researching it ; he noted that he was not very confident in playing the role . Indonesian Idol winner Ihsan Tarore was cast as the young Ahmad Dahlan , while the lead singer of the band <unk> , Giring Ganesha , was cast as Dahlan 's <unk> <unk> ; it was the feature film debut for both . Giring also wrote a song for the film , titled " Allah <unk> <unk> " ( " Allah , the All @-@ Pure " ) , over a period of two days . 
