快拿扇來 Bring Out The Fan Quickly
說不了，八戒趕上罵道：「我把你個結心癀！快拿出扇來，饒你性命。」那牛王只得回頭，使寶劍又戰八戒。说不了，八戒赶上骂道：「我把你个结心癀！快拿出扇来，饶你性命。」那牛王只得回头，使宝剑又战八戒。
逐句解 Line by line
Before he had done speaking, Eight Rules came up cursing: "You knot-hearted murrain!
Eight Rules cuts straight across the speech before it is finished. 說不了 takes 了 as liǎo, the verb "to finish", under a "can/cannot" frame with 不 — not the light le the character carries almost everywhere else. Nothing marks the site: 了 is dipping-tone as liǎo and unstressed as le, and 不 is bù before either. 癀 huáng is a murrain, a cattle disease, which makes the insult species-specific in the way all this chapter's abuse is.
"Bring out the fan quickly and I will spare your life."
饒 is to spare or pardon. The offer is the same one the local god made a passage earlier, stripped of its cosmology and reduced to a threat between two fighters.
The Bull King could only turn back, and fought Eight Rules with his sword again.
只得 takes dé, the settled "have no choice but". 回頭 is literal here rather than figurative: he had broken and run in the previous passage, and is now turned at bay.
Eight Rules cuts across the Bull King's speech before it is finished, and the interruption is the point. 說不了 marks that the grievance about the son, the concubine and the wife was still being stated when a rake arrived. The novel gives the demon his case and then declines to let him complete it.
What replaces the argument is four characters of ultimatum. Where the local god had offered cosmology — three realms informed, ten directions in support — Eight Rules offers only 饒你性命, I will spare your life. The reduction is honest about what the pilgrims are actually doing here.