וַתָּסַר֩ בִּגְדֵ֨י אַלְמְנוּתָ֜הּ מֵֽעָלֶ֗יהָ וַתְּכַ֤ס בַּצָּעִיף֙ וַתִּתְעַלָּ֔ף וַתֵּ֙שֶׁב֙ בְּפֶ֣תַח עֵינַ֔יִם אֲשֶׁ֖ר עַל־דֶּ֣רֶךְ תִּמְנָ֑תָה כִּ֤י רָאֲתָה֙ כִּֽי־גָדַ֣ל שֵׁלָ֔ה וְהִ֕וא לֹֽא־נִתְּנָ֥ה ל֖וֹ לְאִשָּֽׁה׃
And she put off from her the garments of her widowhood, and covered herself with her veil, and wrapped herself, and sat in the entrance of Enaim, which is by the way to Timnah; for she saw that Shelah was grown up, and she was not given unto him to wife.
Rashi on Genesis
ותתעלף AND SHE WRAPPED HERSELF — she veiled her face that he should not recognise her.
Sforno on Genesis
בפתח עינים, at the beginning of two major roads. Such a highway is known as עינים, as we know from Genesis 16,7 על העין בדרך שור, “by the road leading to Shur.”