Sefer HaBahir

They asked him, "Why is it written, 'He took him [Bilaam] to Sedeh-Tzofim [שדה צופים]' (Numbers 23:14)? What is Sedeh-Tzofim [שדה צופים]? [And] it is written, 'Come my beloved, let us go out to the field [השדה]' (Song of Songs 7:12). What is 'the field'? [He answered,] "Do not say 'the field,' rather 'the chest [השידה].'"* [They asked,] "And what is the chest?" [He replied,] "The Blessed Holy One's heart said to Him. 'Come my beloved, let us go out to the chest [השידה],' to journey and not remain in one place."[Ed. - manuscripts and commentators read השידה not השירה. The word השידה ordinarily denotes a chest, box, or cabinet, not the anatomical chest.]