Many among us react based on perception. Perception is opinion or feeling. It is not a reality. When you react to someone with perception and not on reality, there are chances that perceptions can be wrong.
once reacted, words cannot be taken back. Even expressing sorry is not enough. Hurt feeling linger for longer time. This can even spoil relation.
So be aware of full reality before you answer. Let their be response not reaction. Positive response has positive impact.
Simple concept is quite useful in life in all stages of life and in all interpersonal interactions.