Q: What is the connection between Rachel and speech? And why is she silent?
A: The power of speech corresponds to the sefirah of malchut, kingdom. In exile, it is difficult for the Jewish people to express themselves. This is the secret of the verse, "As Rachel (which also means sheep) before the sheep shearers, she is silent." Rachel corresponds to malchut, the power of speech, as well as to Israel and the Divine Presence, the Shechinah. In this verse, Rachel, the "spokeswoman" for the Shechinah, cannot speak, and particularly, cannot pray for the redemption of the Shechinah, because she is in exile.
Nevertheless, as we know, all the rivers flow to the sea, and all the powers of the soul flow to the sea of malchut, speech. Any other power of the soul that a person works on and realizes (such as lovingkindness) will also flow to and find expression in his speech – malchut.