Tears of NaNaCh

HH the Bal Shem Tov said that in order to merit to be kosher Jew living the true reality of HY, it is necessary to pray not to lose your eyesight RL, because it is necessary to cry so much, so many many tears every single day, so many tears that Gd forbid it threatens the eyes....

By Rabbainu people documented how literally streams of tears poured out, e.g. when he circled the bima during Hoashanos he literally left a trail, some sort of stream of tears. Saba related how he saw his mentor Rabbi Yisroel Karduner cry and cry to HY with so many tears that there was literally a puddle, and Saba repeatedly reiterated that he was not exaggerating, on the contrary he was not doing justice to actually giving over the extent of the tears. Also when Rabbi Yisroel Karduner's wife spoke how he went to pray, she said, he went to cry....

There's a great more to be said, this is for starters.

Na NaCh NaChMa NaChMaN MAyUMaN