The nominal adjective "uncircumcised" can be stated as an adjective. AT: "these people who are uncircumcised will come" or "these uncircumcised people will come" (See: [[rc://en/ta/man/translate/figs-nominaladj]])
Here "uncircumcised" represents people who do not belong to Yahweh. AT: "these people who do not belong to Yahweh" or "these heathen Philistines" (See: [[rc://en/ta/man/translate/figs-metonymy]])
# fell on it
Saul probably stuck the handle into the ground and leaned on the point so the sword would go through his body as he fell down. The action is a metonym for the result, death. AT: "killed himself with it" (See: [[rc://en/ta/man/translate/figs-metonymy]])