Tempered glass, like tempered steel, undergoes a well-controlled heating process which increases strength. Thus, when tempered glass is under stress, it will not easily break into jagged shards that can injure. Likewise, a temperate soul—one who is humble and full of love—is also a person of increased spiritual strength.
I really highly doubt you even read these things. We find out about BYU on Friday :) I'm really excited and nervous. Plus, I have to tend this week and the next because my parents are going on a cruise. Lucky them.