What is the ruling on saying, "So-and-so envied me, and I'm sure of it because she hates me," and asking to take from her leftovers, and always describing her as envious?

It is not permissible to accuse people of envy without proof, and mere suspicion is not sufficient proof. If it is definitively proven that someone has afflicted you with the evil eye, then ask him to wash, and you should wash with the water he used; because of the saying of the Prophet, peace and blessings be upon him: "The evil eye is real. If anything were to precede the divine decree, the evil eye would precede it. And if you are asked to wash (for the sake of one who has been afflicted by your evil eye), then wash."

It is recommended to fortify oneself with morning and evening remembrances and to ask Allah for well-being, to recite Al-Ikhlas and Al-Mu'awwidhatayn three times, and to say: "In the Name of Allah, with Whose Name nothing on earth or in the heavens can cause harm, and He is the All-Hearing, the All-Knowing" three times in the morning and evening.

It is also recommended to supplicate with the prayers that the Prophet, peace and blessings be upon him, used to say: "O Allah, I ask You for pardon and well-being in this world and the Hereafter. O Allah, I ask You for pardon and well-being in my religion, my worldly affairs, my family, and my wealth. O Allah, conceal my flaws and calm my fears. O Allah, protect me from before me and behind me, from my right and my left, and from above me, and I seek refuge in Your greatness from being assassinated from beneath me."

Imam Ibn Al-Qayyim mentioned ten reasons for protection from envy: seeking refuge in Allah, fearing Allah, patience with the envious person, reliance on Allah, emptying the heart from being preoccupied with him, turning to Allah and being sincere to Him, sincere repentance from sins, charity and benevolence, extinguishing the evil of the envious person by being kind to him, and purifying monotheism and moving one's thoughts from means to the Cause, Allah, the All-Mighty, the All-Wise, and knowing that all of this is in the hands of Allah.