(Qasas) 28 : 30
فَلَمَّا أَتَاهَا نُودِيَ مِنْ شَاطِئِ الْوَادِ الْأَيْمَنِ فِي الْبُقْعَةِ الْمُبَارَكَةِ مِنَ الشَّجَرَةِ أَنْ يَا مُوسَىٰ إِنِّي أَنَا اللَّهُ رَبُّ الْعَالَمِينَ
Thus, when he came there, he was called from the right side of the valley in a blessed spot from the tree: “Oh Moses, indeed I am Allah, Lord of all worlds".
See explanation 27: 8-9.