Bhagavad Gita 6.6
"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 interpretation
In a moment of stillness, receive this: When you cannot master yourself, you become the person you most have to defend yourself against.
Practical action
Imagine the person you're upset with as a child. Notice if anything softens.
Reflection question
What would peace cost me — and am I willing to pay it?