1 Samuel 15:28
And Samuel said unto him, The LORD hath rent the kingdom of Israel from thee this day, and hath given it to a neighbour of thine, that is better than thou. And Samuel said unto him, The LORD hath rent the kingdom of Israel from thee this day, and hath given it to a neighbour of thine, that is better than thou.
The declaration belongs to the account of Saul's commission to destroy Amalek, a judgment delayed for four hundred years because of Amalek's attack on Israel and continued wickedness. His repeated disobedience and disregard for God's express commands cost him his right to rule, and his second transgression proved him unfit to be king. He denied wrongdoing until the facts were undeniable, then failed to confess his sin and instead regarded himself as mistreated.
Because he rejected the word of the Lord, the Lord rejected him as king and removed the kingdom from him. The tearing of Samuel's mantle as Saul grasped it confirmed the declaration and served as a sign that the kingdom was taken away. The Lord's decision to remove him was firm and would not change, unlike Saul himself.
The kingdom was taken from him and given to a better neighbor, to a better successor, pointing to another who was later identified as David. Saul recognized David as the man who would reign in his place. The declaration made Saul recognize his true condition, but his fear-driven admission and request for pardon was not true repentance, since he cared more about receiving public honor than gaining God's forgiveness and favor.
Saul knew he had been rejected because of his wicked course. He repeatedly foretold his own dethronement and the loss of royal honor for his descendants, who would perish because of his sins, speaking with distracted intensity before his lords and the people. His insistence on his own way led to the loss of his kingdom and honor, and those who persist in having their own way as he did face loss and finally the loss of the soul.