Hamas Called A Murderer "Heroic"

Several days ago, a Palestinian man stabbed two Israelis to death in old Jerusalem.  This attack also seriously wounded a woman and a toddler.  Hamas, the Islamic militant  group that rules Gaza, praised the attack.  It called the attack "heroic."  I just have one question:  What makes stabbing a man and a woman to death, and seriously wounding a toddler and a woman, a "heroic" act?