The ruling on using "law" (if) in the context of wishing

Question:
Honorable Shaykh, this person asks about the use of "law" (if) when it is used to express a wish. What is its ruling?

Answer:
There is nothing wrong with that. The Messenger (peace and blessings be upon him) said, "If I had known in advance what I know now, I would have slaughtered the sacrificial animals with you and made it a red mark." He said this during his Hajj (peace and blessings be upon him), in the Farewell Pilgrimage. So he wished (peace and blessings be upon him) that he had not brought the sacrificial animals and had not entered the state of ihram for a combined pilgrimage, but rather that it had been better for him to enter the state of ihram for a tamattu' pilgrimage. Yes.