Musar sobre Isaías 48:15

The Midrash continues: G–d called to Moses whereas G–d did not call to Abraham. How are we to understand this in view of Genesis 22,15: ויקרא מלאך ה' אל אברהם; Clearly G–d did call to Abraham. We must answer that it is no disgrace for the king to speak with his innkeeper. When G–d spoke to Moses He did not do as He did when He spoke to Abraham, but the angel first called to Abraham (to tell him G–d was about to speak to him). Rabbi Avin says that G–d said: "I am the caller and it is I who is speaking." We know this from Isaiah 48,15: אני אני דברתי אף קראתיו והביאותיו והצליח דרכו, "I, I have spoken, I called him; I have brought him and make him successful in his mission." Thus far the Midrash.