ויחי יעקב. לָמָּה פָּרָשָׁה זוֹ סְתוּמָה? לְפִי שֶׁכֵּיוָן שֶׁנִּפְטַר יַעֲקֹב אָבִינוּ נִסְתְּמוּ עֵינֵיהֶם וְלִבָּם שֶׁל יִשְׂרָאֵל מִצָּרַת הַשִּׁעְבּוּד, שֶׁהִתְחִילוּ לְשַׁעְבְּדָם; דָּבָר אַחֵר: שֶׁבִּקֵּשׁ לְגַלּוֹת אֶת הַקֵּץ לְבָנָיו, וְנִסְתַּם מִמֶּנּוּ. בִּבְ"רַ:
ויחי יעקב AND JACOB LIVED — Why is this section (Sidra) totally closed? Because, comprising as it does an account of the death of Jacob, as soon as our father Jacob departed this life the hearts and eyes of Israel were closed (their eyes became dim and their hearts troubled) because of the misery of the bondage which they then began to impose upon them. Another reason is: because he (Jacob) wished to reveal to his sons the date of the End of Days (i.e. when Israel’s exile would finally end; cf. Rashi on Genesis 49:1), but the vision was closed (concealed) from him (Genesis Rabbah 96:1).