Saul said, They have brought them from the Amalekites: for the people spared the best of the sheep and of the oxen, to sacrifice to Yahweh your God; and the rest we have utterly destroyed.
Samuel spoke what the writer recorded in 1 Samuel 14:22-23 in poetic form, indicating to all that God had inspired what he was saying. God frequently communicated oracles through the prophets in such exalted speech (cf. Genesis 49; Deuteronomy 33; et al.). These classic verses prioritize total obedience and worship ritual for all time. God desires reality above ritual. Sacrificing things to God is good, but obedience is "better" because it involves sacrificing ourselves to Him. The spared animals Saul offered to God were voluntary sacrifices.