The numerical value of mayim - water is 100
mem, yud, yud, mem - 40+ 10+10+ 40
100 symbolizes completion. It is also the product of 10 x 10 (10 sephirot nested in 10 sephirot.) You could say that 100 represents the whole of the creation including the upper and lower oceans, or of all divine knowledge, or both.
Yofi- beauty also equals one hundred. Yofi can also be written p(eh) yud, yud - the mouth of G-d. Creation was performed by the mouth of G-d so to speak.
A mikveh is a gathering of water which can be used for ritual immersion and hence, purification. To be a kosher mikveh the water must be connected directly to its subterranean sources. When the water is thus connected it has a quality of "mayim chayim"- literally, "alive water". However, if we take a glass and remove some of this water it does not have this property while in the glass. If we fill a cavity with glasses of water, a cavity at least of the minimum permissible volume for a mikveh, although it looks like a mikveh it is not a mikveh because it does not have the connection to the source. Only certain conduits are kosher connectors. One has to study the details of the laws of mikvehs to gain a deeper understanding here.
However, if we pour that glass of water back into the same mikveh or pour it into another mikveh, then the water which was in the glass regains the status of "living water". This is quite remarkable, but look what happens when we apply it to divine wisdom.
In terms of 'deep sources'- 'deep' can also mean 'high' or perhaps related to the Jungian 'transpersonal'- beyond our conscious.
Let's say someone is truly connected to the source. He possesses a mikveh within- in a sense, he is that mikveh . His knowledge, has a quality of "living knowledge". If he gives or writes words of Torah he is, as it were, putting some of that water into a glass. The water loses its "living" status but it's still live giving, sustaining in other ways. Someone else can take in that water, that knowledge and benefit from it, but the knowledge will not be fully alive. However, if that second person is also connected, then the water is again "living water". The person adds to his own inner mikveh.
The vitality is not really lost from the water in transit, but rather, it is in a state of concealment. When it is together with wisdom connected with the source, then thelife/light within it is revealed. Thus it is said that the Ohr haganuz- the hidden light- is hidden in the Torah amongst other times and places. It's there, but we have to make the effort to connect with the source in order to reveal the light in the words of Torah we hear. When we encounter a new gem of Torah widom we feel "wow!" we've perceived some of that light.
Mikveh has many other fascinating and wonderful connections. Look at the letters mem, kuf, vav, heh. The root is kuf vav. Kuf itself represents transcendance, relates to holiness and has a number of 100. (Rav Yitzhak Ginsburgh's book elaborates on this). Vav represents a connection between up there and down here. Of course this is not a literal spatial description but a metaphorical one. The kav, kuf, vav, is involved in the mystery of creation and tzimtzum, desribed in detail in Rabbi Aryeh Kaplan's book "Inner Space". In brief, it's a connection between the perfect oneness of G-d and the fragmention of our perceived world.
Another related word is tikva - hope, anticipation. .
kiviti lishuascha Hashem - "I have anticipated your salvation, Hashem". Here we see kiviti in terms of a yearning for universal connection.
We can now assemble all the elements of this contemplation and see them in their place.
Mikveh- a pool of water connected to a deeper source.
Kuf, vav- a line connecting the transcendant to perceived reality.
Tikvah- a yearning and anticipation for the future, for divine redemption and ultimate connection.