What is the ruling on the statement that knowing envy is not part of the knowledge of the unseen, and that jinn can recognize the envied person by looking at him or into his eyes, and does this statement necessitate disbelief or is it a sin?

Knowing whether a person is afflicted by envy is not a claim to the knowledge of the unseen, nor does claiming it constitute disbelief. This is because envy has signs and symptoms that appear in the health, psychological, and financial condition of the envied person. The Prophet, peace and blessings be upon him, affirmed the Companions when they mentioned to him that children had been affected by the evil eye, and he commanded them to perform Ruqyah (definition), as in the hadith (definition) of Umm Salamah and Asma bint Umays.

The symptoms of envy appear on the self, such as introversion, isolation, decreased intelligence, and feelings of distress; or on wealth, such as business setbacks and spoilage of goods; or on the body, such as lethargy, emaciation, loss of appetite, and pains. It is not necessary for all symptoms to appear on the envied person. As for jinn knowing this by looking at a human, we have no knowledge of that, and it is not permissible to seek the help of jinn in Ruqyah.