We learn why people must involve God and His Shechinah in their rejoicing.
The Light of the Holy One participates in our rejoicing by virtue of our meditative read of this passage. The negative force called (do not pronounce this name) Samael and all his band are banished eternally from this world. The Shechinah, on one level of understanding, is connected to our immune system and to the ozone layer of the planet. Hence, here we evoke the presence of the Shechinah to filter out and ward off harmful entities (Samael and his band) that bring sickness, airborne diseases and destruction to our midst. Our personal and global immune systems are fortified forevermore. The protective energy that our parents naturally imbue to us is resurrected here, even if our parents are watching over us from the next world.