Possible meanings are 1) Samson is so thirsty he could literally die. AT: "But now I will die of thirst and my body will fall into ... uncircumcised." or 2) Samson exaggerates how thirsty he is by asking if he will die of thirst. AT: "But now will you allow me to become so weak from my thirst that I fall into ... uncircumcised?" (See: [[rc://en/ta/man/translate/figs-hyperbole]])
This means to die because you have not drank enough and therefore, you do not have enough water in your body. (See: [[rc://en/ta/man/translate/figs-idiom]])
# fall into the hands of those who are uncircumcised
The phrase "fall into the hands" means to be captured. "Those who are uncircumcised" refers to the Philistines and with the word "uncircumcised" emphasizing that they do not worship Yahweh. AT: "be captured by those godless Philistines" (See: [[rc://en/ta/man/translate/figs-idiom]])