This Shabbat is Parshat זכור and it is a Torah obligation to hear the Torah reading about Amalek. It can be made up on Purim day by hearing the Torah reading before the Megillah as that reading also speaks about Amalek.
The Haftarah for פרשת זכור discusses Shaul Hamelech and his inability to completely destroy Amalek, for which he lost his kingdom. The Amalekite king was named אגג and Haman is referred to as המן האגגי. Shaul made excuses for his behavior when, in reality, he was afraid of the people.
The lesson learned from this episode is that when one is kind to his enemies, he will be cruel to his friends. (Shaul showed such cruelty when he had the Kohanim of Nov put to death.)
This lesson of the connection between kindness and cruelty holds true on many levels. Simply put, when one is overly kind with one who doesn't deserve it, such as disciplining our children, we are really being cruel to them. Shabbat Shalom and Happy Purim!