We read one story yesterday about Saul's fall from grace. Today we get a second story. This whole idea of total destruction of an enemy by God's command is extremely troubling. The idea is that in certain settings every person, animal and piece of property had to be destroyed. It was said to be "devoted to the Lord" and the way it was devoted was through destruction. Ideas like this in the Bible are dangerous and hard to deal with constructively. For me it helps to remember that these passages were written much later than the events they describe, in a time when Israel was in danger because they were seduced by the gods and ways of life of their neighbors. Passages like this emphasize the call to be different from the world around them. There is not any archeological evidence that suggests that Israel ever actually destroyed enemies like this, so it's likely that the idea came later, in response to new threats.
Apart from the disturbing command, the thing to take away from the story is that Saul and his soldiers didn't obey God's command; instead, they kept the valuable things that their enemies had. Selfishness took the people away from following what God had commanded.
blessings as you follow God today,