Хасидус к Тегилим 73:26

When one has a heart, 'place' has no significance at all. In fact, such a person is the place of the world. Because divinity rests in the heart, as it says (Psalms 73:26) "[G'd is] the rock of my heart." With regards to the Holy One it is written (Exodus 33:21) "There is a place with me" - that is, He is the place of the world, and the world is not his place.

And he who wants to continue in the interpretations of the Torah, must, from the beginning, continue saying to himself warm things, like coals of fire. And the words continue [out] from the upper [supernal] heart, in the aspect of "the rock of my heart" (Psalms 73:26). And he must pour out his words [speech] in prayer before Hashem Yisbarach, and by his prayer receives the pity of the mercy of Hashem Yisbarach on him, and his upper [supernal] heart opens, because the essence of mercy is in the heart, and there will be an outpouring of words from his upper [supernal] heart, and by the words he will continue in the interpretations of the Torah also from there.

The second soul in Israel is truly "a part of God above," as it is written: "and he blew into his nostrils a soul of life"(Genesis 2:7); "And You blew it into me." (Siddur, Morning Prayer). It is written in the Zohar "he Who blows, blows from within him," that is to say, from his inwardness and from his innermost being. For it is of his inward and innermost vitality that a man emits through blowing with force.