קבלה על בראשית 18:1

And she [Tamar] sat on Petach Eynayim [the entrance to the eyes] (Gen. 38:14) - Just as you say "and he [Avraham] sits at the entrance [petach] of the tent" (Gen. 18:1), and it is written "And Ad-nai passed over the entrance [petach]" (Ex. 12:23), and it is written "open [pitchu] for me the gates of righteousness etc" (Ps. 118:19) [meaning] that all eyes of the world turn to that opening. [...]