This was said by Long Yi.
It's not that Situ Yongjie doesn't trust Long Yi, but the prince hadn't spoken personally, so he always felt a lack of security. He didn't want to lose both the madam and the troops.
Indeed, although it was expressed nicely as all being for the prince's illness, deep down he was still concerned about the alliance with the War Prince's Mansion. After all, Xuexue had wandered among the common people for over ten years, and he always felt he owed her. Now, for the sake of his son, he was marrying her off to the dying War Prince, and he always carried a sense of guilt.
There was a sense of unwillingness he hadn't even detected.
Unwilling to sacrifice his daughter's lifelong happiness, yet unable to save his son's life.
Situ Yongjie desperately looked at Long Rui lying on the bed, hoping for a promise: "Prince?"
Long Rui, weakly, said another sentence: "Mm...I...I will handle...it well, go."
Finally, he raised his weak hand and waved it.