Deuteronomy 25: 17 “Remember what Amalek did to you on the way as you came out of Egypt, 18 how he attacked you on the way when you were faint and weary, and cut off your tail, those who were lagging behind you, and he did not fear God. 19 Therefore when the Lord your God has given you rest from all your enemies around you, in the land that the Lord your God is giving you for an inheritance to possess, you shall blot out the memory of Amalek from under heaven; you shall not forget.
The Amalekites, for absolutely no reason, had previously acted with cruelty towards the Israelites, and had had a complete and utter disregard for God. God commanded the Israelites to destroy them (just and honest weights were just discussed previously in this passage), not as personal revenge (for that generation was gone), but for God's glory. God had been patient in delaying this punishment until now, allowing lots of time for the Amalekites to repent, but they did not.
So, were the Israelites obedient?
We will read later in 1 Samuel 15 that Saul was ordered to carry this out, but he failed to do so completely, and that was the at which God rejected him as king.
Later, David destroyed many of them, and in Hezekiah's time the Simeonites took care of the rest (1 Chronicles 4:43) because God's judgment will always be fulfilled as He intends.
Are we obedient?
God's plans will always come to pass, whether we are obedient or not. But when we are obedient, we get the blessing of being used by Him and get to experience the closeness of relationship that comes with living in obedience.
Tomorrow's Bible In a Year Passage: Deuteronomy 28-29; Mark 14:54-72