"Whoever Allah guides, no one can mislead, and whoever He causes to stray, no one can guide"

The Shaykh :"Whoever Allah guides, no one can mislead" means that if Allah the Exalted decrees that a person will be guided, no one can prevent him from Allah's guidance. Likewise, if a person is actually guided, no one can mislead him, provided that Allah the Exalted has decreed guidance for him. This negates the possibility of misguidance in both the negative and affirmative senses, meaning that if Allah has decreed guidance for someone, no one is able to mislead him. This is the first point.
Second: If a person is actually guided, no one can take him out of guidance into misguidance as long as Allah has decreed that for him.
The converse is "and whoever He causes to stray, no one can guide", meaning that if Allah Blessed and Exalted has decreed that a person will be misguided, no one can guide him. Allah the Exalted said: "O Allah, guide us among those You have guided." This phrase, "no one can guide him," is what came in the Sunnah. As for the saying of some people, "and whoever He causes to stray, you will not find for him a guiding protector," that is indeed found in the Qur'an, but it did not come in this hadith.