תניא אמר ר' יהושע בן פרחיה בתחלה כל האומר עלה לה אני כופתו ונותנו לפני הארי עתה כל האומר לי לירד ממנה אני מטיל עליו קומקום של חמין
As a corollary to the statement of the Sages with regard to one who is jealous and wants the position of another, it is taught in a baraita that Rabbi Yehoshua ben Peraḥya said: Initially, in response to anyone who would say to me: Ascend to the position of Nasi, I would tie him up and place him in front of a lion out of anger for his suggestion. Now that I have become the Nasi, in response to anyone who tells me to leave the position, I would throw a kettle [kumkum] of boiling water at him out of anger at his suggestion.
שהרי שאול ברח ממנה וכשעלה בקש להרוג את דוד
It is human nature that after one ascends to a prestigious position he does not wish to lose it. As evidence of this principle, Saul initially fled from the kingship, as he did not wish to be king, as stated in the verse: “When they sought him he could not be found…Behold he has hidden himself among the baggage” (I Samuel 10:21–22). But when he ascended to the kingship he tried to kill David, who he thought was trying to usurp his authority (see I Samuel, chapters 18–27). [Menachos 109b]
