The ladder that leads to the Kingdom is hidden within you, and is found in your soul. Dive into yourself, and in your soul you will discover the rungs by which you are to ascend.
St. Isaac the Syrian, quoted by Coniaris, interiorizes the ladder of ascent entirely, identifying its rungs with the soul’s own depth rather than any external structure.
, Philokalia: The Bible of Orthodox Spirituality, 1998thesis