Since Jing Yiran failed to marry Shanggun Ning, he also refused to help Shangguan Zheng.
Shangguan Zheng spent two days in indecisiveness, but finally submitted the letter of resignation, trying to avoid being expelled because of Jing Yichen's threat. But he wasn't happy.
He resigned with an excuse that he was very sick, claiming that he would return to the position when he became fit again. If Jing Yichen truly exposed his past crimes to the Province, then his life would be totally ruined.
But both the sons of Family Jing liked his daughter.
So even if Shangguan Ning wasn't close to him, she wouldn't just leave him at their disposal.
He knew his daughter well. She looked distant, but her heart melted easily. She believed in loving the family.
Earlier, when he had forced his daughter to get engaged with Xie Zhuojun, she disagreed. But when he had threatened her with Huang Lihan's doom, she got engaged with Xie Zhuojun obediently.