Using Weak Hadiths in Sermons and Exhortations

Question:
What is the opinion of the honorable Shaykh regarding using weak hadiths in sermons and exhortations?

Answer:
There is no harm in that. The scholars have stated that it is permissible to mention weak hadiths in sermons and books, by way of citation and reminder, not by way of reliance, but with a formulation of weakness. One must not assert with certainty from the Prophet (peace and blessings be upon him) except with authentic hadiths.
If the hadith is weak, one says: “It is narrated from the Prophet (peace and blessings be upon him),” or “It is mentioned,” or “It is narrated from the Messenger,” or “It is mentioned from the Messenger (peace and blessings be upon him);” because benefit can be derived from the weak in encouraging good and warning against evil. This is the meaning mentioned by the majority of the scholars of knowledge, and al-Hafiz al-‘Iraqi (may Allah have mercy on him) mentioned this in his famous book, al-Alfiyyah, where he said:
They were lenient in narrating, other than in matters of fabrication,
without clarifying the weakness, and they saw
its clarification in rulings and beliefs
from Ibn Mahdi and more than one [scholar].
And if you wish to transmit it, whether it is weak or
doubtful, not by their chains,
then bring a formulation of weakness so it is narrated, and assert
the transmission of what is authentic, like saying, “Know that…”

And the meaning of “they were lenient” is that they were lenient in narrating the weak, without clarifying its weakness, if it contains exhortation, encouragement, and warning.
As for what agrees with the authentic hadiths in rulings, such as what is lawful, what is forbidden, what is obligatory, and what is recommended, this is not cited as evidence except with the authentic.