Jacob uses the words "soul" and "heart" to refer to himself and is saying that other people—and perhaps God also—honor him so much that he does not wish to join with those who make plans to do evil. (See: [[rc://en/ta/man/translate/figs-synecdoche]])
These two phrases mean basically the same thing. Jacob combines them to emphasize that he does not want to participate in their wicked plans. AT: "I certainly will not join with them to make any plans" (See: [[rc://en/ta/man/translate/figs-parallelism]])
Jacob compares the men of Shechem to oxen. This emphasizes the strength of the men and that Simenon and Levi killed them as if the men were just animals. AT: "they slaughtered men like they slaughter oxen" (See: [[rc://en/ta/man/translate/figs-metaphor]])