Or HaChaim on Genesis 27:6/אור החיים על בראשית כ״ז:ו׳

1 ורבקה אמרה אל יעקב, And Rebeccah said to Jacob, etc. The reason that the Torah introduces the verse with the conjunctive letter ו is to tell us that Rebeccah agreed with the Holy Spirit which had conveyed this conversation between Isaac and Esau to her.

2לאמר, הנה שמעתי. to say, "here I have heard," etc. She wanted to make sure that Jacob realised that she had only just become aware of what had transpired between Isaac and Esau and that she could not be accused of having allowed too much time to elapse to take countermeasures. Jacob had enough time to carry out his mother's instructions.

3אחיך לאמר, "your brother, saying." She did not mean that Esau was a true brother of Jacob in character; she used the word "your brother" to indicate that just as Isaac plotted with Esau, she now did the same thing with Jacob.

4She also used the word לאמר to protect herself since she had not quoted Isaac's words to Jacob verbatim. She meant that she had told Jacob the gist of Isaac's words to Esau.