Jewish Mysticism
Why is it written, “Seek out His countenance continually” (1 Chron. 16-11)? This is to teach that the Holy One, blessed be He, at times is seen and at times not seen, at times heard and at times does not want to hear, at times responds and at times does not want to respond, at times can be sought and at times cannot be sought, at times is found and at times not found, at times is close and at times not close. How is this? He was seen by Moses, as it says, “The Lord spoke to Moses [face to face as one speaks to another]” (Exod. 33-11). Afterwards He was hidden from him, as it says, “Show me Your glory” (ibid. 18). And similarly He was seen by Israel at Sinai, as it says, “And they saw the God of Israel” (ibid. 24-10), and it says, “And the vision of the glory of the Lord” (ibid. 17). Afterwards He was hidden from them, as it says, “For you have seen no image” (Deut. 4-15), and it says, “You heard the sound of the words [but perceived no shape, nothing but a voice]” (ibid. 12).

Translated by Elliot Wolfson in Through a Speculum that Shines- Vision and Imagination in Medieval Jewish Mysticism, Princeton- Princeton University Press, 1994.