All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
When defining the black seed, Imaam Ibn Al-Qayyim said, "It is authentically reported by Al-Bukhari and Muslim on the authority of Abu Salamah from Abu Hurayrah that the Messenger of Allaah said: "This black cumin is healing for all diseases except As-Sam and As-Sam is death.".
This seed is called Shoniz in the Persian language. It is called black cumin or Indian cumin. Al-Harbi narrated from Al-Hasan that he said, "It is mustard". Al-Harawi also reported that it is the green seed which is a fruit of the terebinth tree. Both are incorrect. The correct view is that it is Shoniz and has many benefits.
The narration of the Prophet saying, "It is healing for all diseases" is like the words of Allaah The Almighty, (which means): {Destroying everything by the command of its Lord.} [Quran 46:25]. This means everything that can be destroyed.
As regards how to use it, there are no restrictions in that. It can be eaten, boiled with water, ground, and kneaded with other things. Its usage for healing some diseases need special methods of preparation as indicated by Ibn Al-Qayyim .
He said further, "Black cumin is a dry seed that removes flatus, cures favus, useful in curing leprosy, quartan fever and phlegm. It opens blockages and dries wet stomach. If it is ground and kneaded with honey and then drunk with hot water, it melts renal and vesicle calculus. It causes urine, menstrual blood and milk to flow easily if it is drunk continuously. If it is boiled with vinegar and rubbed on the stomach, it kills favus. If it is kneaded with fresh or cooked colocynth water, it has great effect in removing worms. It cures cold if ground and put in a piece of cloth and then continuously inhaled. Its oil is good for intestinal worms. If it is drunk with water it helps in curing difficulty in breathing. If it is used to bandage the head, it cures headache caused by cold. If seven of its seeds are soaked in milk, and a jaundiced person snuffed it, it benefits him a lot". [Zaad Al-Ma'aad, 4: 297]
As for Zaytoon (olives) Ibn Al-Qayyim said in the same book, "At-Tirmithi and Ibn Majah reported on the authority of Abu Hurayrah that the Prophet said: 'Eat the oil (of Zaytoon) and rub yourselves with it, for it is from a blessed tree.'"
Al-Baihaqi and Ibn Majah also reported that the Prophet said: "Season your food with olive oil, for it is from a blessed tree".
Ibn Al-Qayyim explained some of the benefits of olive saying, "It is useful to remove poison from the body, it empties the bowel and drives away worms. The olive oil that is extracted with water is less hot, is gentler and more beneficial. All kinds of olive oil smoothes the body and delays graying of hair. Salty olive water prevents blistering of burns and strengthens the gums. Its leaves help in curing erysipelas and dirty sores and many other problems."
As for its usage, it is squeezed and has its oil and water extracted and then eaten alone or with any other food. If you need to know more about the benefits of black seed and olive, you can consult books by specialists.
Allaah Knows best.