וַיְהִ֗י כַּאֲשֶׁ֨ר כִּלָּ֣ה יִצְחָק֮ לְבָרֵ֣ךְ אֶֽת־יַעֲקֹב֒ וַיְהִ֗י אַ֣ךְ יָצֹ֤א יָצָא֙ יַעֲקֹ֔ב מֵאֵ֥ת פְּנֵ֖י יִצְחָ֣ק אָבִ֑יו וְעֵשָׂ֣ו אָחִ֔יו בָּ֖א מִצֵּידֽוֹ׃
И было, когда Исаак прекратил благословлять Иакова, а Иакова еще почти не было в присутствии Исаака, отца его, и пришел Исав, брат его, с охоты его.
Rashi
יצא יצא [JACOB] WAS YET SCARCE GONE OUT — this means, as one went out the other came in (Midrash Tanchuma, Toldot 11).
Rashbam
ויהי אך יצא יצא, this detail has been recorded to illustrate the miracles which were performed in order to enable Yaakov to obtain this blessing. If Esau had returned just one minute sooner, Yaakov would not have secured this blessing.
Radak
ויהי...מצידו, as if the Torah had written מצודו, “from his hunting expedition.” The Torah chose a noun instead of a verb in its infinitive form. We find a similar construction in Numbers 10,2 ולמסע את המחנות, which means the same as ולהסיע את המחנות, “and to set the camps (army groups) in motion.” We also find such a construction in Ezekiel 17,9 למשאות אותה משרשיה, “and to remove it from its roots.” A third example which comes to mind is Numbers 23,10 ומספר את רבע ישראל, “or number the animals born to the livestock of Israel?” The word מספר is used there as if the Torah (Bileam) had said לספר, “to count.” [I assume that when the Torah quotes a human being, such as here, G’d dictated Bileam’s words to Moses, seeing that neither Moses nor any other Jew had heard a single one of Bileam’s blessings. Ed.]