Is it permissible to add to the supplication in the qunut of the witr prayer beyond what was reported from the Prophet (peace and blessings be upon him)?

Question:
May Allah reward you, Honorable Shaykh. There are many questions; I will present to you whatever is feasible of them. This questioner says: What is the ruling on adding to the qunut of the witr prayer beyond what was reported in the hadith of the Prophet (peace and blessings be upon him) teaching al-Hasan (may Allah be pleased with him)?

Answer:
There is no harm in adding to the supplication in the qunut beyond what was reported from al-Hasan, but one should avoid what some imams (may Allah guide them) do, which is being contrived and inventing words that were not reported. One should avoid this and supplicate with the supplications reported in the Book and the Sunnah, and not invent a supplication on his own or based on his own juristic preference. He should also not prolong it; prolonging is not permissible. Prolonging that burdens the ma'mum (those praying behind the imam) is not permissible. "Let the one who is the imam of the people shorten it." So he should not prolong it, nor be contrived with supplications that were not reported in the Book and the Sunnah. Yes.