The Yerushalmi writes that when Yosef was about to sin with Eishes Potiphar, it was his mother’s image that appeared to him (posted about this here). Why his mother’s image in particular? The Shem m’Shmuel writes that Eishes Potiphar’s intent was just as much l’shem shamayim as Tamar’s, about whom we read earlier in that same parsha. In fact, astrological signs pointed to her being destined to be together with Yosef (and indeed, her daughter did marry Yosef.) She thought that they were spiritual soulmates. It dawned on me that there was a parallel to Rachel Imeinu here: remember that Leah was crying because she thought she was destined to marry Eisav while Rachel was supposed to be Ya’akov’s true wife. Despite what was “supposed” to happen, Rachel saw her sister Leah being brought to the chupah and decided it was better to give over the simanim and delay being with Ya’akov than to embarrass her sister. This was the dmus d’yukah that Yosef saw: even if Eishes Pothiphar’s insight as to their destiny was true, it did not mean he needed to act on it at that moment. Like his mother did, Yosef was being called on to wait and not act, no matter what the future was predicted to hold. Destiny would happen on its own schedule; the future need not be forced. The great test of Yosef’s character was to see if he could rise to the same challenge that his mother had faced.This same challenge follows Yosef. “V’lo yachol Yosef l’hisapek…” After revealing himself to his brothers, Yosef cries on Binyamin’s neck and Binyamin cries on his shoulders, an act which Rashi interprets as mourning for the churban habayis. Sefas Emes (link) explains that because Yosef could not delay revealing himself any longer the tikun was incomplete and churban and galus were therefore necessary. Rachel suffered and held back walking to the chuppah for the sake of Leah. Yosef tried, but in the end was not his mother’s equal.
Maybe this is why when Yosef originally presented his dream to Ya’akov in which he saw the stars, the sun, and the moon bowing to him, Ya’akov knew it had to be false because the moon, Rachel, could not bow. Of course the pshat is that Rachel couldn’t bow because she was dead, but maybe there is a remez here that although Yosef could rise above his brothers and even to some degree above his father, when it came to meeting the challenge his mother faced, he would remain a notch below.Why is this midah the sticking point for Yosef? Perhaps it is because although Rachel showed tremendous patience in stoically and silently waiting for his 7 years of labor to finish until she could marry Ya’akov, and then waiting again as she watched her sister Le’ah go to the chuppah in her place, when it came to having children, Rachel’s patience was at a limit. Rachel came to Ya’akov and demanded, “Hava li banim v’im ayin meisah anochi.” (30:1).
None of this is muchrach – I’m just tossing my speculations out there.