The ninth Hebrew letter, Teth [ט], is the symbol of all the goodness of creation. It is also the first letter of the word tov, meaning “good”. Technically, first in our Western, left-to-right way of reading is actually last in Hebrew, but you get what I mean. This is what the word tov looks like in Hebrew letterforms:
טוב
(You can see the teth in orange at the end, which is actually the beginning.) When God saw that “it was good” seven times in Genesis 1, that’s tov each time, and the initial letter of the word has come to be associated with all that creative goodness in its many manifestations.
Variants on the word tov, each with the initial teth, also show up six times in this ninth section of Psalm 119.