It is in the last part of the Bible, the "Writings," that the root k-b-l achieves its greatest prominence, appearing eleven times and always in the sense of "receptivity/acceptance."
The first verse in this collection appears in the Book of Proverbs:
Hear counsel and receive instruction that you may be wise in your end
The conjunction in this verse appearing between "hear" and "receive" alludes to the importance of binah, "understanding"–the feminine emanation of Divine light (sefirah) associated with the sense of hearing.
The association between "understanding" and "hearing" is based upon the role that understanding plays in helping differentiate truth from untruth through a process of inner contemplation–a process which, like that of hearing, requires a certain sensitivity to nuance.
Hearing is associated with the feminine by virtue of its operational motif; hearing is a process of receiving and absorbing, the essential modes of feminine response. These are the qualities that are necessary in order to comprehend the subtle and often-elusive Divine truths conveyed through Kabbalistic thought.
The above verse from Proverbs, which links the term Kabbalah to the "acceptance of instruction" alludes to an important character trait that predisposes one to properly absorb higher wisdom. Referred to in Chassidic sources as the trait of ego-submission, the willing acceptance of God’s instructions conveyed in the Torah is an absolute prerequisite for becoming a vessel capable of containing Divine wisdom.
This is alluded to in the verse itself when it states that the purpose of "hearing" and "accepting" is "in order that you will become wise in your end." The "wisdom of the end" is an allusion to the hidden wisdom of Kabbalah, which is increasingly revealed as we come closer to the End of Days.