Like Sarah before her, Rachel had her bondwoman, Bilhah (who was also her half-sister), marry her husband, hoping that in this merit she would also be blessed with children. After Bilhah had two sons, Leah – who had stopped bearing children by then – had her bondwoman, Zilpah (who was Leah’s and Rachel’s other half-sister), marry Jacob, with the same hope. Zilpah also had two sons; after this, Leah’s fertility was indeed restored, and she had two more sons and a daughter. Rachel then finally conceived and bore her first son, whom she named Joseph.
Bringing Home the Estrangeds
וַתִּקְרָא אֶת שְׁמוֹ יוֹסֵף לֵאמֹר יֹסֵף ה' לִי בֵּן אַחֵר: (בראשית ל:כד)
[Rachel] named him Joseph [“May He add” in Hebrew], saying, “May G‑d add another son for me.” Genesis 30:24

Rachel’s prayer sums up Joseph’s spiritual mission in life – to turn “another,” i.e., a seeming stranger, into a “son.” This mission expresses itself in three ways: First, in making the mundane world – which appears to be separate from G‑d – acknowledge and celebrate its Divine source. Second, in personal repentance, through which we transform ourselves from estranged “others” into “sons” who belong. Third, in reaching out to those who seem estranged from G‑d, revealing to them that they are G‑d’s precious children, for whom living life according to G‑d’s plan is simply natural.1

Let us not feel inadequate or incapable of effecting such transformations, for we do not work unaided. Rachel said, “May G‑d add for me another son” – we are merely G‑d’s instruments, and it is really He who lovingly welcomes His estranged children home.2