And Reuben went in the days of Sivan, in the time of wheat harvest, and found (Yaveruchin) mandrakes in the field; and he brought them to Leah his mother. And Rahel said to Leah, Give me now of thy son's mandrakes.
Reuben, the Mandrakes, and the Wheat Harvest in Sivan
Targum Pseudo-Jonathan on Genesis 30:14