Answer: A line is a scale inside me where I build all the inclinations, thoughts, desires, and attitudes in a straight manner. Everything that is now being revealed in me, in my Kelim, becomes built in accordance to the Light that comes to me.
If there is a clear, precise agreement between the Light that now shines on me and the vessels I put in order according to the Light, this means I am built according to a line. That’s because inside of me there is a heap of qualities and the Light that comes to me helps me build myself along a line. Previously I was like a sphere, and then I asked the Light that comes in a straight form to shine inside me in the form of a line and to put me into the same order.
The Surrounding Light (Ohr Makif) shines all around. When I ask it for corrections that are built as a straight line, the Light becomes “stretched out” into a line, as do I in conformity with it. This transition depends on whether a person is able and willing to demand this structure from the Light. The Light’s action lies above knowledge, but if a person receives the force to overcome, if he bestows and gives himself over to the Light with full agreement, then the Light orders all the components of his soul according to their importance.
From the 1st part of the Daily Kabbalah Lesson 9/28/10, “What is Silver, Gold, Israel, the Nations in Work”