إِذْ نَادَاهُ رَبُّهُWhen his Lord called him,meaning, He called out speaking to him.بِالْوَادِ الْمُقَدَّسِin the holy valley,meaning purifiedطُوًىTuwaAccording to what is correct, it is the name of a valley, as preceded in Surah Ta Ha.So, He said to him:اذْهَبْ إِلَى فِرْعَوْنَ إِنَّهُ طَغَى