Where is He knocking? And what is the meaning of His knocking?
The knocking is the beating of the heart. The `knocking' arouses an inner feeling that someone outside is seeking the one inside. The knocking reminds a person that the Beloved One wants us; He seeks our benefit. The knocking comes to awaken a person so as to prepare the vessels to accept and contain that beneficence.
When does one hear the knocking?
When he dedicates his ego, his self, to his Beloved — for then he is able to hear that knocking and feel the urge to draw close to Hashem. This is the special power of Elul, when even a minimal preparation can already enable one to feel intimacy with the Creator for in these days, "my Beloved is for me."
A person who creates ways to prove and strengthen his rapport with Hashem, such as designating a set place for prayer, taking pains that his prayer be wholesome and organized and not a rote sequence but rather a concentrated effort, maintaining a studied focus on the commencement of the zman and on the individual seder, applying himself to the study of Mussar — such a person shows that the beginning is important, and his motivation will surely have a positive effect upon him.
When one consecrates his 'self', his 'ego', to his Beloved', he is able to hear that knocking (from the teachings of the Mashgiach HaRav Moshe Aharon Braverman zt"l about Elul).
