Rashi on Genesis 34:25/רש"י על בראשית ל״ד:כ״ה

1שני בני יעקב TWO OF THE SONS OF JACOB — They were his sons (the sons of Jacob, a wise and clever man), but they acted as any man named Simeon and Levi would do — as other people would do who were not his sons — for they did not take counsel with him (Genesis Rabbah 80:10).

2אחי דינה DINAH’S BROTHERS — because they risked their lives for her they are designated as her brothers (Genesis Rabbah 80:10)

3בטח IN SECURITY — because they (the men of Shechom) were ill. The Midrashic explanation, taking בטח in the sense of confident, is: that they relied upon the strength (i.e. the merits) of the old man (Jacob) (Genesis Rabbah 80:10).