I heard Messenger of Allah ﷺ saying, "If someone takes seven ʿajwah dates in the morning, neither magic nor poison will hurt him that day."  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ: «مَنْ تَصَبَّحَ سَبْعَ تَمَرَاتٍ عَجْوَةً لَمْ يَضُرُّهُ ذَلِكَ الْيَوْمَ سَمٌّ وَلاَ سِحْرٌ۔»