Four Corners
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
The face of a written instrument. That which is contained on the face of a deed (without any aid from the knowledge of the circumstances under which it is made) is said to be within its four corners, because every deed is stlil supposed to be written on one entire skin, and so to have but four corners. To look at the four corners of an instrument is to examine the whole of it, so as to construe it as a whole, without reference to any one part more than another.
2 Smith, Lead. Cas. 295.