In order to understand this we must first explain what the two Mazalot mentioned above are. There are thirteen attributes of Mercy which G-d revealed to Moshe. (Parshat Ki Teesa) They are:
1. E-L – Benevolent G-d
2. Rachum – Compassionate
3. V’Chanun – and Gracious
4. Erech – Long (slow)
5. Apayim – Suffering (to anger)
6. V’Rav Chesed – and Abounding in Kindness
7. V’Emet – and Truth
8. Notzer Chesed – He Preserves Kindness
9. L’Alaphim – for two thousand generations
10. Noseh Avon – Pardoning Iniquity
11. VaPeshah – and Transgression
12. V’Chata’a – and Sin
13. V’Nakeh – and He Cleanses.
The source of these thirteen attributes is in Keter of Arich. It is for this reason that they are called the thirteen attributes of mercy. Because they are higher than Chochmah of Arich which, as mentioned above, (in ch. 32) is the source of the laws of the Torah, they therefore have the ability to overturn a Divine decree from harshness to leniency, through mercy. This is how Moshe was able to arouse G-d’s mercy, and appease G-d in His wrath against the Jewish people. It was specifically by appealing to G-d’s mercifulness as exemplified by these thirteen attributes of mercy.
The eighth and the thirteenth attributes, Notzer and V’Nakeh, are called Mazalot. The Hebrew word Mazal comes from the root Nozel which means “To flow down”. They have this name because it is from these two attributes that influence flows down to Chochmah and Binah.