The source of the custom is in the deception which Laban practised upon Jacob, giving him the wrong sister to marry and requiring him to continue as a servant for years more in order to win the girl he really wanted.
The story is told in next week’s sidra, but this week we meet two elements of the custom – the bride modestly covering herself with a veil (Gen. 24:65) and the family blessing her in the words, Achotenu, heyei l’alfei r’vavah – “Our sister, may you grow into thousands of myriads” (Gen. 24:60).
The words literally convey the wish that she may have many descendants, and this generation of Jews ought to find special significance in the prayer that the Jewish people may be helped to grow as the result of every Jewish marriage.
How about the continuation of the verse, V’yirash zar’ech et sha’ar son’av – “May your descendants seize the gate of their enemies” (Gen. 24:60)?
The idea repeats a blessing found in last week’s reading (Gen. 22:17). The gate of an ancient city was not only the doorway but also the meeting place. Everything happened there including sessions of the elders and sittings of the judges. Possessing the gate was a mark of authority. The prayer asks God to give the bride progeny and power.
Why the bride and not her husband? According to Rashi and other commentators, in days when men were polygamous, the bride was told, “May your family’s destiny be fulfilled through you and not through another wife”.