Daily Zohar 4141
Holy Zohar text. Daily Zohar -4141

Hebrew translation:

143. שָׁנִינוּ, כָּל אוֹתָם שְׁלֹשִׁים יָמִים נִשְׁמָתוֹ יוֹצֵאת מִמֶּנּוּ בְּכָל לַיְלָה, וְעוֹלָה וְרוֹאָה אֶת מְקוֹמָהּ בְּאוֹתוֹ הָעוֹלָם, וְאוֹתוֹ אָדָם לֹא יוֹדֵעַ וְלֹא מַשְׁגִּיחַ וְלֹא שׁוֹלֵט בְּנִשְׁמָתוֹ כָּל אוֹתָם שְׁלֹשִׁים יוֹם כְּמוֹ שֶׁהָיָה בַּתְּחִלָּה, שֶׁכָּתוּב (קהלת ח) אֵין אָדָם שַׁלִּיט בָּרוּחַ לִכְלֹא אֶת הָרוּחַ וְגוֹ’. אָמַר רַבִּי יְהוּדָה, מִכְּשֶׁמַּתְחִילִים אוֹתָם שְׁלֹשִׁים יוֹם, צֶלֶם הָאָדָם נֶחְשָׁךְ, וְהַדְּמוּת שֶׁנִּרְאֵית בָּאָרֶץ נִמְנַעַת.
144. רַבִּי יִצְחָק הָיָה יוֹשֵׁב יוֹם אֶחָד עַל פִּתְחוֹ שֶׁל רַבִּי יְהוּדָה וְהָיָה עָצוּב. יָצָא רַבִּי יְהוּדָה וּמָצָא אוֹתוֹ בַּשַּׁעַר שֶׁלּוֹ שֶׁהָיָה יוֹשֵׁב וְעָצוּב. אָמַר לוֹ, מַה יּוֹם זֶה מִשְּׁאָר יָמִים?
145. אָמַר לוֹ, בָּאתִי אֵלֶיךָ לְבַקֵּשׁ מִמְּךָ שְׁלֹשָׁה דְבָרִים. אֶחָד – שֶׁכַּאֲשֶׁר תֹּאמַר דִּבְרֵי תוֹרָה וְתַזְכִּיר מֵאוֹתָם דְּבָרִים שֶׁאֲנִי אָמַרְתִּי, שֶׁתֹּאמַר אוֹתָם בִּשְׁמִי, כְּדֵי לְהַזְכִּיר אֶת שְׁמִי. וְאֶחָד – שֶׁתְּזַכֶּה אֶת יוֹסֵף בְּנִי בַּתּוֹרָה. וְאֶחָד – שֶׁתֵּלֵךְ לְקִבְרִי כָּל שִׁבְעַת הַיָּמִים וּתְבַקֵּשׁ בַּקָּשָׁתְךָ עָלַי.


Zohar Vayechi
Continued from previous DZ
During these thirty days, the soul comes out of the body every night and rises to see her place in the upper world. The person doesn’t know or have control over his soul during all these thirty days, as it is written;
Ecclesiastes 8:8
“אֵין אָדָם שַׁלִּיט בָּרוּחַ לִכְלוֹא אֶת הָרוּחַ וְאֵין שִׁלְטוֹן בְּיוֹם הַמָּוֶת וְאֵין מִשְׁלַחַת בַּמִּלְחָמָה וְלֹא יְמַלֵּט רֶשַׁע אֶת בְּעָלָיו.”
“No one has power over the spirit to retain the spirit, And no one has power on the day of death. There is no release from that war, And wickedness will not deliver those who are given to it.”
Rabbi Yehuda said that when these thirty days begin, the image (Heb. צֶלֶם, pronounced, Tzelem) of a person gets dark, and the shape of the Tzelem is no longer seen in this world.

Rabbi Yitzchak was sitting at Rabbi Yehuda’s door one day, and he was sad. Rabbi Yehuda went out and saw him at his door. He asked him, what happened that today you are not like on other days?

Rabbi Yitzchak told him, I have come to you to ask you for three things: one, when you say the words of the Torah and remember what I said, say them in my name. Also, you will teach Torah to my son, Joseph. Also, go to my grave all seven days of mourning and pray your prayer for me.

This Zohar starts a famous story about how rabbi Shimon controlled the angel of death. Rabbi Yitzchak was a Tzadik and could see his Tzelem. When he stopped seeing it, he went to his friend, Rabbi Yehuda, and asked him to support his soul after his death by mentioning his name during Torah studies. Also, to pray for him, especially during the seven days after his death.
Rabbi Yitzchak did not have a fear of death. And he knew that only the Torah could help him above death. Also, teaching his son Torah would earn him merits because the children are on the same spiritual line, and everything they do affects the line, positively or negatively.
When we study Torah in this world, we support the souls of those in the family that passed away, including those we mention by name.
“Thus you have learned: everyone who says a thing in the name of him who said it brings deliverance into the world.” – Megila 15a

Also, from Ethics of the fathers