The Torah tells us Jacob told Rachel he was her kinsman (Genesis 29:12). The Targum Pseudo-Jonathan fills in a conversation between them.
Jacob explained to Rachel that he had come to live with her father to marry one of his daughters. Rachel's response was not romantic. It was a warning. Thou canst not dwell with him, for he is a man of cunning. Rachel knew her own father. She had grown up watching Laban bargain, scheme, and trap. She loved Jacob enough, on the first day of meeting him, to tell him to turn around.
Jacob's reply is startling in its confidence. I am more cunning and wiser than he; nor can he do me evil, because the Word of the Lord is my Helper.
Two claims packed into one sentence. First: Jacob will match Laban's shrewdness with shrewdness of his own. He has already outmaneuvered Esau twice — over the birthright and the blessing. He knows how to operate inside a family of tricksters. Second and more important: his real defense is the Memra, the Word of God, who promised at Bethel to keep him in every place he went (Genesis 28:15). Jacob is not relying on his wits. He is relying on the covenant.
Rachel runs home. She does not tell her father that Jacob is wise. She tells him that Rebekah's son has come. That is enough to send Laban running out.
The takeaway: Rachel warned Jacob on day one about twenty years of pain. He walked into the house anyway, because he knew Who was walking in with him.