“מְבָרֵךְ רֵעֵהוּ, בְּקוֹל גָּדוֹל–בַּבֹּקֶר הַשְׁכֵּים: קְלָלָה, תֵּחָשֶׁב לוֹ”
“He that blessed his friend with a loud voice, rising early in the morning, it will be counted a curse to him”
Proverbs teaches us that a person that blesses his friend in a loud voice early in the morning, it would be considered for him as a curse. A man should connect to his soul to YHVH with the morning blessings and prayer before greeting another person, unless the other person is a Tzadik.
The Zohar explains that God created us with a holy soul that have three levels of light, Nefesh, Ruach and Neshama. All three levels participate in every action a person does. They are considered connected as one, like in the upper levels of Binah (Neshama), Zeir Anpin(Ruach) and Malchut(Nefesh). Neshama is the higher level and it can get impure by negative actions.
After sleep, our soul is still under the influence of the force of death that was in the body during the night sleep. Blessing another person while in such state, draws light that goes to the other side and that is considered as idol worshipping. Greeting a Tzadik is an act of elevation and considered as a person bless YHVH.
The first thing a person should do upon waking up is to sit on the bed and thank God for returning his soul to him.
מוֹדֶה אֲנִי לְפָנֶיךָ מֶלֶךְ חַי וְקַיָּם, שֶׁהֶחֱזַרְתָּ בִּי נִשְׁמָתִי בְּחֶמְלָה. רַבָּה אֱמוּנָתֶך
“I give thanks before you, eternal living King, for You have mercifully restored my soul within me; Your faithfulness is great.”
Modeh ani lefanecha melech chai vekayam, she-he-chezarta bi nishmati b chemla, raba emunatecha.
Then we wash hands (three alternates), then read the 18 morning blessings that restore the life force from YHVH in our body. These blessings and the Shema Yisrael prayer purifies the blood and soul level of Nefesh, strengthening the hold of the soul over the body.