Bukhari

Hadith Commentary:
➊
Muhallab said that this dream is self-interpreted because the word "sawda’" (blackness) is derived for its interpretation, that is, the word "sawda’" and "da’" (disease) clearly indicate a severe illness.
From this word, the interpretation of the dream becomes apparent.
The severe illness departed from Madinah Tayyibah and moved to a settlement called Juhfah.
Accordingly, the Messenger of Allah (sallallahu alayhi wa sallam) supplicated:
“O Allah! Make Madinah pleasant and beloved for us, and transfer its epidemic diseases to Juhfah.”
(Sahih al-Bukhari, Virtues of Madinah, Hadith: 1889)
➋
Hazrat A’ishah (radi Allahu anha) stated that during those days, Madinah Tayyibah was gripped by epidemic diseases, so after the supplication of the Prophet (sallallahu alayhi wa sallam), the climate of Madinah Tayyibah became pleasant.
(Fath al-Bari: 12/532)

Hadith Commentary:
Al-Muhallab said: This is a self-interpreted dream, and it is among those in which a parable is struck. The aspect of the parable is that a part of the name "al-Sawda" (the black woman) is taken from the word "saw’" meaning evil, and "da’" meaning disease, so her departure was interpreted according to what her name combined. (Fath al-Bari)

That is, al-Muhallab said that the dream is self-explanatory. In it, a black woman named Sawda was seen, and the word "saw’" means evil and "da’" means disease, so her very name is such that the interpretation is apparent from it.

The severe disease left Madinah and went to a settlement called al-Hujfah, which is six miles away from Madinah. The climate of this settlement is, to this day, bad and humid, and all praise is due to Allah, the climate of Madinah al-Munawwarah is very excellent and healthful.

Hadith Commentary:
➊
The scholars of dream interpretation have said that to see something in a dream that is black from all sides is extremely disliked, and the dishevelment of hair refers to the state of fever, because it causes shivering in the body. Especially, the disheveled hair of a black woman is extremely terrifying.
(Fath al-Bari: 12/532)

➋
Aisha radi Allahu anha narrates that when we migrated to Madinah Tayyibah, Abu Bakr as-Siddiq radi Allahu anhu and Bilal radi Allahu anhu suffered from severe fever.
At that time, in the valley of Bathan, there flowed a dirty, foul-smelling stream, due to which Madinah Tayyibah was, in those days, gripped by epidemic diseases.
The Messenger of Allah sallallahu alayhi wa sallam supplicated, so its atmosphere became moist and pleasant, and the epidemic diseases, by the mercy of Allah ta'ala, were transferred to Hujfah.
(Sahih al-Bukhari, Virtues of Madinah, Hadith: 1889)

Benefits and Issues:
➊
In the beginning, the climate of Madinah was not good.
Allah Ta'ala gave glad tidings to His Prophet (sallallahu alayhi wa sallam) through a dream that the epidemic would be removed from Madinah, and so it happened.

➋
In a dream, an ugly person signifies illness or calamity, and a handsome person signifies comfort and blessing.
And Allah knows best.