Midrash su Genesi 29:12

(Ib. b.) And Esther still did not tell her nation. R. Chama said: What is the meaning of the passage (Job 36, 7) He withdraweth not his eyes from the righteous. i.e., as a reward for her modesty, Rachel merited that King Saul descended from her; and as a reward for Saul's modesty he merited that Esther descended from him." Wherein was Rachel modest? It is written (Gen. 29, 12) And Jacob told Rachel that he was her father's brother. Was he then her father's brother? Indeed, he was the son of her father's sister! This means, he asked her: "Will you marry me?" "Yes," she answered, adding, "but my father is a trickster, and he will deceive you." To this he answered: "I am his brother in trickery." And she asked him: "Are righteous men permitted to walk in the ways of deceit (to deal fraudently with a deceiver)?" "Yes," answered he, "for it is written (Ps. 18, 27) With the pure Thou wilt show Thyself pure, and with the perverse Thou wilt wage a contest." He then asked Rachel: "How can he cheat me?" And she replied: "I have an elder sister, and he will not let me marry before her." So he confided some signs to him by which he could distinguish her. And when Leah was brought in her stead, Rachel said: "My sister will be put to shame." So she confided in return the signs to her. And this explains the Passage, And it came to pass that in the morning. Behold, it is Leah; i.e. Until the morning he knew it not, because Leah knew the sign which Jacob had confided unto Rachel, which she told to him. And therefore Rachel was rewarded that Saul descended from her. And what was Saul's modesty? It is written (I Sam. 10, 16) And Saul said unto his uncle, he told me that asses had been found, but of the matter of the kingdom, whereof Samuel had spoken, he told him not. For this he was rewarded that Esther descended from him. R. Elazar said again in the name of R. Chanina: "When the Holy One, praised be He! decrees greatness for a man, it is for him and his descendants to the end of all generations; as it is said (Job 36, 7) He doth establish them forever, and they are exalted. But if he becomes proud, the Holy One, praised be He! will lower him, as it is said (Ib. 8) If they be bound in fetters, and if they be entangled in the cords of affliction."