Don't console a mourner after he has visibly consoled himself: Moed Katan 27b
Children will eulogize a dead pet, not consume it: Shabbat 90b
A person won't remain in an unpredictably dangerous situation: Yevamot 112b
People living in exile are forced to be externally beautiful, since their honor is not known: Shabbat 145b
Not being the bearer of bad tidings: Megillah 15a