[24b middle] Gemarah: An Onein (someone waiting to bury a deceased relative) and a Mechusar Kippurim (someone waiting to bring a sacrifice after purification) need immersion to permit the eating of Kodesh but not Terumah. The Rabbis required them to undergo immersion before esting Kodesh in order to focus their attention to remove impurity.
T’s Lesson: Before Rosh Hashanah and Yom Kippur people have the Minhag (custom) to immerse in a Mikvah (ritual bath). Since we are entering a new state of a new year, we should have a new mindset of starting over with a clean slate. We need to rid ourselves of our previous states and shed our old selves and sins. We should keep these thoughts in mind over the holidays to start fresh and new.