In 1 Samuel 15:9, Saul spares Agag and the best livestock — the specific disobedience referenced here as failing to execute God's wrath on Amalek.

In 1 Samuel 15:23-26, Samuel declares Saul rejected as king due to his rebellion — the very rejection explained here as the LORD's doing.

In 1 Samuel 15:28, Samuel tells Saul the kingdom is torn from him that day — the specific 'thing' the LORD has done to Saul in 28:18.

In 1 Chronicles 10:13, Saul's death is attributed to his breach of faith — specifically not keeping the command, which is the Amalek disobedience.

In 1 Kings 20:42, a prophet rebukes Ahab for sparing a devoted enemy, mirroring Saul's failure with Amalek — both lose their lives for it.

In Jeremiah 48:10, a curse is pronounced on those who do God's work slackly or keep back the sword — describing Saul's half-hearted obedience against Amalek.