And Samuel said, Hath the LORD as great delight in burnt offerings and sacrifices, as in obeying the voice of the LORD? Behold, to obey is better than sacrifice, and to hearken than the fat of rams. – 1 Samuel 15:22

That which the Lord commands we should do-just that, and not another thing of our own devising. How very curiously people try to give God something else instead of what He asks for! The Lord says, “My son, give Me thine heart,” and they give Him ceremonies. He asks of them obedience, and they give Him will-worship. He asks faith, and love, and justice; and they offer ten thousand rivers of oil, and the fat of fed beasts. They will give all except the one thing which He will be pleased with: yet “to obey is better than sacrifice, and to hearken than the fat of rams.” If the Lord has given you true faith in Himself, you will be anxious not so much to do a notable thing as to do exactly what God would have you to do. Mind your jots and tittles with the Lord’s precepts. Attention to little things is a fine feature in obedience: it lies much more as to its essence in the little things than in the great ones. Few dare rush into great crimes, and yet they will indulge in secret rebellion, for their heart is not right with God. Hence so many mar what they call obedience by forgetting that they serve a heart-searching, rein-trying God, who observes thoughts and motives. He would have us obey Him with the heart, and that will lead us, not merely to regard a few pleasing commands, but to have respect unto all His will. Oh, for a tender conscience, which will not willfully neglect, nor presumptuously transgress! ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2195.cfm