Whether the Hadith of Warding Off Poison and Sorcery With Seven Dates Is Restricted to 'Ajwa, and the Hadith of a House With No Dates
As for the hadith "a house with no dates in it, its inhabitants are hungry" — this is a separate hadith from the Prophet ﷺ, and it is authentic, narrated by Imam Muslim. It is found in Sahih Muslim, though despite being in Muslim there has been some difference of opinion about it — but it is nonetheless in Muslim.
As for his ﷺ saying, in the hadith of the two Sahihs, "Whoever has breakfast with seven dates, from 'Ajwa dates, will not be harmed that day by poison or sorcery" — the scholars, may Allah have mercy on them, differed over whether specifically 'Ajwa dates are required for warding off poison and sorcery. One group said this is truly a condition — this is the view of the majority — they require 'Ajwa dates specifically, as stated in the report, making this a condition for warding off poison and sorcery. Another group said this is merely preferable, not a strict condition, so that if one has breakfast with dates other than 'Ajwa, the effect would still appear, with benefit in warding off poison and sorcery.
They argue that the wordings differ — one narration mentions "al-'aliyah" dates, another mentions "Medina" dates, another mentions "'Ajwa" dates unrestricted — and they support this by saying legislation is meant for all Muslims, and this virtue extends to all levels of society. For if it were restricted to 'Ajwa dates, its benefit would be limited to a specific group, whereas the principle in legislation is that it applies to all people; it is a general message for all, and no group is singled out over another. They also argue that a similar effect has been found in dates other than 'Ajwa in warding off poison and sorcery.
This view is stronger than that of the majority. It can be traced to the legal principle that mentioning something specific within a general ruling does not restrict it — so the mention of "dates" generally, alongside the mention of "Medina," "al-'aliyah," and "'Ajwa," does not restrict the ruling, because this falls under mentioning something specific within a general ruling, which does not restrict it. A similar example is his ﷺ saying, "The earth has been made for me a place of prostration and a means of purification" — and in Muslim's narration, "and its soil" — which does not restrict "the earth has been made for me [pure]," because it is likewise a case of mentioning something specific within a general ruling.
Based on this, the apparent and most correct view, and Allah knows best, is that this legislated virtue applies to all types of dates, and "whoever has breakfast with seven dates will not be harmed by poison or sorcery" applies broadly. However, 'Ajwa dates have a stronger effect — the softer type of date is generally more potent in warding off many things, and this is known both empirically and medically, supporting the view that the ruling is not restricted to 'Ajwa dates specifically.