"For one who has conquered the self by the Self, the Self is a friend; but for one who has not, the Self remains as an enemy in hostility."
Modern explanation
When the day pushes against you, remember: When you cannot master yourself, you become the person you most have to defend yourself against.
Practical application
Lower your voice and slow your speech by half. Your nervous system will follow.
Reflection question
If I respond from my best self, what does that response sound like?