Jonathan is trying to get Saul to think carefully about what he is doing. This can be translated as a statement, and the words "should he be put to death" can be translated in active form. AT: "You have no good reason to put him to death. He has done nothing wrong." or "You have no good reason to kill him. He has done nothing wrong." (See: [[rc://en/ta/man/translate/figs-rquestion]])
This "second" is an ordinal number which refers to two. AT: "the second day of the new moon festival" (See: [[rc://en/ta/man/translate/translate-ordinal]])