The introduction to Rabbi Ruttenberg's book features an English translation of a Hebrew poem she is singing at the beginning of a Shabbat service. The translation seems to be unique to the book, and so I couldn't find its actual Hebrew name. Here's the full quote:
As the melody runs its course and begins to ebb, I move into the first piece of the liturgy, a medieval love poem full of longing for union with the Divine. Beloved of my soul, compassionate parent, draw Your servant to Your will. Let Your servant run like a gazelle to bow down before Your splendor. Let Your affection be sweeter than a honeycomb or any other taste. Splendorous one, most beautiful radiance of the world, my soul is sick with love for You.