“שִׂימֵנִי כַחוֹתָם עַל לִבֶּךָ כַּחוֹתָם עַל זְרוֹעֶךָ כִּי עַזָּה כַמָּוֶת אַהֲבָה קָשָׁה כִשְׁאוֹל קִנְאָה רְשָׁפֶיהָ רִשְׁפֵּי אֵשׁ שַׁלְהֶבֶתְיָה”
“Put me like a seal over your heart, Like a seal on your arm. For love is as strong as death, Jealousy is as severe as Sheol; Its flashes are flashes of fire. The very flame of the LORD (YH).”
The congregation of Israel that is Malchut asks God to make her a ‘seal’ on his heart. The ’seal’ is the ring of truth that represents the supernal light of Chokmah and Binah. This light removes the Klipot that hide the Light of the center column and like a stamp, imprints its light in Malchut.
The Tefillin of the head represents the ‘seal’ and the ring, which is the strap that surrounds the head. ‘Like a seal on your arm’ refers to the Tefillin of the hand. It points to the heart that is in the center column.
The ‘ring’ of the head Tefillin, draw the ‘seal’ to the left and right of the heart, center. Malchut receives this light from two sides. One is from the heart, center, and the second is form the Left arm, so the entire body is full of the Light from the upper seal that is Chokmah and Binah.
“For love is as strong as death” is the love of the soul to the body and it is difficult to separate them. So is the love of the Israelites in Malchut to the Holy One Blessed be He. Their connection can never be separated. For this reason, the Tefillin on the left arm explains Songs 2:6 “שְׂמֹאלוֹ תַּחַת לְרֹאשִׁי וִימִינוֹ תְּחַבְּקֵנִי,” “His left hand is under my head, and his right arm embraces me.”
“Jealousy is as severe as Sheol.” Jealousy comes from love, and the lack of love is as severe as the lower level of Gehennam. Sheol is the one before the lowest level, and it is tough to be released from that level. The lowest level is called ‘אבדון’ ‘Avedon’ that means ‘lost.’ Without the love of God, we are lost.
“Its flashes are flashes of fire, The very flame of the LORD (YH).” This is the flame that comes out of the Shofar that is an aspect of Binah and includes air and water. The flame represents the Light of Chokmah that comes from the Left column that has the aspect of Fire.
יה YH are the two letters of the YHVH name that represent Chokmah and Binah. When the flame comes out in Malchut, it burns the judgments in the world with the jealousy to the Holy One Blessed be He.
It’s a process to reach a level of ‘Devekut’ to the Holy One Blessed be He. Devekut is a point of love to God that is hard to separate. A man that puts Tefillin every day cannot imagine skipping a day without Tefillin. Even if he goes on a short vacation, he will carry his Tefillin bags with him. A woman that lights Shabbat candles every Friday would feel great pain if she misses one Shabbat. Similarly with other spiritual connection. Once we reach a level of love and happiness with our studies and meditations, we keep desiring the relationship like two lovers seeking the presence of each other.
The Light of YHVH creates a bond that is like a connection between the body and the soul. When they nourish each other, they can’t think about separation. This love burns a great fire in the soul that seeks only growth.
More about Devekut on Wikipedia