מַיִם אַחֲרוֹנִים, “Final waters”
The Zohar and the sages teach that the process of ‘First waters’ is related to the washing of the hands before the meal. It is a precept, which we do with the blessing of “Al Netilat Yadayim”.
‘Middle waters’ is optional and it is done when we eat dairy followed by meat (The other way around is not Kosher). It is better to wash hands in between so we won’t mix the two types of energy on our hands. It is also recommended to wash hands between eating fish and meat.
‘Last waters’ is a must and it is the process of washing the fingers before making the final blessing of the meal.
In this case we remove the negative energy of the Klipot that is connected to our hands when we eat the physical food to satisfy our physical desires. After washing the fingers we can proceed to make the final blessing, ‘Birkat Hamazon’.
“וְהִתְקַדִּשְׁתֶּם וִהְיִיתֶם קְדֹשִׁים, כִּי קָדוֹשׁ אָנִי”
“Sanctify yourselves therefore, and be ye holy; for I am holy”
The instruction above to be holy is constructed from three words with the same root of ‘קדש’, ‘Holy’.
Another aspect of ‘final water’ is revealed in the Zohar. When a man releases semen from his body into the woman’s ‘vessel’ it is considered as ‘first waters’. This action connects to the precept of “Be fruitful and multiply…”. The woman’s vessel reacts with ‘final waters’. The Holy one Bless be He produces the ‘middle waters’ and ‘freezes’ them to form the body of the child.
“הֲלֹא כֶחָלָב, תַּתִּיכֵנִי; וְכַגְּבִנָּה, תַּקְפִּיאֵנִי”
“Hast Thou not poured me out as milk, and curdled me like cheese”
Milk is the aspect of semen produced from the body. ‘Cheese’ is גבינה in Hebrew and it has the word בינה ,Binah and בניה, which means building.