Charles Ellicott Commentary Genesis 31:20

"And Jacob stole away unawares to Laban the Syrian, in that he told him not that he fled." — Genesis 31:20 (ASV)

Jacob stole away unawares. — Hebrew, stole the heart. But the heart was regarded by the Hebrews as the seat of the intellect, and so to steal a man’s understanding, like the similar phrase in Greek, means to elude his observation.