A small Targumic detail in Genesis 30:16 captures how Leah knew her husband had returned from the fields.
She heard the voice of the braying of the ass. Jacob's donkey. Leah recognized the sound before she saw the man. She had spent years learning the rhythm of her husband's arrivals, and now she could identify his approach by the bray of his animal alone.
The Targum gives us this small domestic reality because it matters to the story. Leah is not idly standing at the door. She is listening — has been listening, for years — for exactly this moment. The night of the mandrakes has been promised to her. She does not want to miss her turn.
So she goes out to meet him and speaks a line the Torah preserves in all its bluntness. Thou wilt enter with me, because hiring I have hired thee with my son's mandrakes from Rachel my sister.
Leah is claiming her night. She has purchased it, in the currency of a handful of mandrake roots, from her sister. There is no romance here, no subtlety. Only a woman whose husband has walked past her tent too many nights, now calling out her contract rights.
The Midrash (Niddah 31a) says that because Leah went out to meet Jacob with such raw desire for a child of her own, she was rewarded with Issachar — a son whose tribe would become the foremost scholars of Torah in Israel. Her desire was not shameful. It was holy.
The donkey's bray, the trade of mandrakes, the blunt proposition at the tent door — every detail preserved by the Targum builds toward a single point: the tribe of Torah study was born because Leah refused to let another night pass without her husband.
The takeaway: sometimes the ears of love hear what the eyes cannot. Leah heard the donkey, and the tribe of Issachar was born.