In dharūhu, the imperative addresses a plural group; wāw is the subject marker and the attached -hu is the object: “all of you, leave him.” Takuffū comes from k-f-f, a root associated with checking or restraining an action.
The first verb issues a direct command; the second appears within a condition about desisting. Together they show the elder's practical purpose: stop pursuing the man and prevent the loss from escalating.