Is frowning in the face of others or dealing with them with displeasure considered a sin that leads to wrongdoing, even if it does not result in any harm, insult, lying, injustice, deception, or backbiting, and is the Prophet, peace be upon him, considered a wrongdoer when he frowned in the face of the blind man?

Frowning at people contradicts kindness and cheerfulness. It is narrated in the Hadith: "The most incapable of people is he who is incapable of prayer, and the most miserly of people is he who is miserly with the greeting of Salam."

Al-Manawi said: The most miserly of people is he who is miserly with the Salam greeting to whomever he meets, for Salam is light in burden and great in reward. And miserliness with a smile is more severe, and it deprives its owner of goodness and reward.

If frowning harms others, it is a deficiency that deprives one of good. And if the matter reaches the point of distorting one's face, it is forbidden. Allah Almighty says: "And do not turn your cheek in scorn toward people." (Quran 31:18) Turning one's cheek in scorn is an act of arrogance towards people, belittling them, and turning away from them with an arrogant face.