By pondering Hashem’s unfathomable and infinite greatness through applying to this meditation the faculty of Daat (knowledge), i.e., through immersing oneself in the subject of Hashem’s greatness with the depth of Daat, so that one not only understands this greatness, but actually feels it, his faculties of Chochmah and Binah engaged in pondering Hashem’s greatness will give birth to an awe of Hashem in his mind, and dread of Hashem in his heart.
There will also be born of this contemplation a love of Hashem, burning in his heart like a flame, like fiery flashes. His soul will thirst and pine with desire and longing to cleave to the blessed Ein Sof with all his heart, soul, and might — as it is written:
‘ואהבת את ה’ אלקיך בכל לבבך ובכל נפשך ובכל מאדך.’
“With all your heart” means that the heart is filled with the love of Hashem;
“with all your soul” implies that the love spills over beyond the heart, to affect all the organs of the body — the feet, for example, will move with alacrity to do a mitzvah;
“with all your might” means loving Hashem to the point where one will sacrifice his life for Him.
(Lessons in Tanya Chapter 9)