I am reading the book 鵺の家 by 廣嶋玲子, and I have a question about the usage of the words と言って and だ in the following.
My attempt at translation:
However, yesterday the older brother said the following. There shall be no more running. For I have discovered a treasure. We will be living in this land. Everyone (in the family) rejoiced and wanted to hear about that treasure. But the young head of the family (the older brother) while repeating what he said, did not disclose any details at all. And today he whispered in secret into the ear of his younger sister. He said, I will first show the treasure, which I discovered in the middle of the forest, to you. The girl was glad that he felt that way.
I am not sure about と言って。In the last sentence why is there だ? Could we replace だ with に or 見ると? What about 言って。Thank you for help.