Towards the beginning of Parashat Vayeshev, the Torah describes Yosef as a "na'ar et benei Bilha ve-et benei Zilpa neshei aviv" – "a lad with the sons of Bilha and the sons of Zilpa, his father's wives" (37:2). Rashi explains this clause as referring to two distinct characteristics. First, Yosef acted as a na'ar, immaturely, paying inordinate attention to his appearance. Secondly, he was frequently "with the sons of Bilha and the sons of Zilpa," who found themselves shunned by their older brothers, the sons of Leah. Yosef, despite being a son of Rachel, the most beloved of Yaakov's wives, nevertheless befriended and dealt kindly with the sons of Bilha and Zilpa. According to Rashi, then, this description is intended to reveal the seeds of contention that would later develop into bitter tension between Yosef and his older brothers.
In a generally similar vein, the Rashbam explains that Yosef befriended the sons of Bilha and Zilpa and thereby brought upon himself the enmity of the sons of Leah.
Abarbanel, however, explains this verse much differently, claiming that the word na'ar in this context means "serving." Yosef, in his humility, lowered himself before even the sons of Bilha and Zilpa, treating them with respect and even as his overlords. All the more so, then, did he conduct himself respectfully towards the sons of Leah. According to Abarbanel, this verse seeks to extol Yosef's virtues, as he humbled himself before all his brothers, including the sons of Bilha and Zilpa. For this reason the Torah makes a point of identifying Bilha and Zilpa as neshei aviv – Yaakov's wives. The Torah emphasizes that Yosef treated these wives' sons no differently as he did the sons of Leah, recognizing that Bilha and Zilpa had no lower a status in the family than Rachel or Leah.
Rav Yaakov Mecklenberg, in his Ha-ketav Ve-ha-kabbala, cites Abarbanel's interpretation of this phrase, but advances a different theory regarding its purpose in the narrative. Whereas Abarbanel saw this description as simply extolling Yosef's humility, Rav Mecklenberg claimed that it sheds light on the ensuing events. The fact that Yosef conducted himself with such humility even towards the sons of Bilha and Zilpa proves the prophetic nature of his dreams of power and authority. As opposed to other commentators, who understood Yosef's dreams as a natural result of his ambitions of leadership, Rav Mecklenberg contends that to the contrary, these dreams directly contrasted with Yosef's attitude towards his brothers. He harbored no ambitions of power or prestige, feeling content working as a lowly, humble servant to his brothers. Precisely for this reason he realized that his dreams were of prophetic significance, as they could not possibly have originated from any personal desire for authority, and he therefore felt compelled to share these dreams with his brothers.
The brothers, of course, rashly concluded that Yosef's dreams reflected his longing to rule over them, and were naturally incensed. This story thus emphasizes the importance of giving the benefit of the doubt rather than immediately attributing sinister motives to our family members and peers. What people around us say or do can occasionally appear offensive despite never being intended as such. According to Rav Mecklenberg, Yosef's brothers harbored resentment towards him because of a simple misunderstanding of his perspective and intentions. Had they given Yosef the benefit of the doubt and sought to understand his motives, rather than immediately presuming his megalomaniacal lust for power, this tragic conflict could have been avoided, and the twelve brothers could have lived together in peace, harmony and mutual understanding.