Deep of night

Deep Deep, n. 1. That which is deep, especially deep water, as the sea or ocean; an abyss; a great depth. [1913 Webster]

Courage from the deeps of knowledge springs. --Cowley. [1913 Webster]

The hollow deep of hell resounded. --Milton. [1913 Webster]

Blue Neptune storms, the bellowing deeps resound. --Pope. [1913 Webster]

2. That which is profound, not easily fathomed, or incomprehensible; a moral or spiritual depth or abyss. [1913 Webster]

Thy judgments are a great deep. --Ps. xxxvi. 6. [1913 Webster]

{Deep of night}, the most quiet or profound part of night; dead of night. [1913 Webster]

The deep of night is crept upon our talk. --Shak. [1913 Webster]