Is it necessary to do wudoo’ before doing ghusl for making oneself pure (tahaarah)

If you are referring to the ritual bath of ghusl, then
the answer is as follows:

Al-Bukhaari reported in al-Saheeh (248) from Aaishah
that when the Prophet
(peace and blessings of Allaah be upon him) did ghusl to purify
himself from janaabah (impurity following intercourse), he would start by washing his
hands, then he would do wudoo as for prayer, then he would dip his fingers into the
water and make the water reach the roots of his hair, then he would pour water over his
head three times, scooping the water up with both hands, and then he would pour water over
his entire body.

Al-Haafiz said in al-Fath (1/248): he would start
by washing the parts of the body ordinarily washed in wudoo in order to honour them,
and so as to include both kinds of purification, the minor and the major

Al-Haafiz also said (1/362): Al-Bukhaari also understood this to
mean that it is waajib when making ghusl to purify oneself from janaabah to wash oneself
once, and that the one who does wudoo with the intention of making ghusl and then
washes the rest of his body does not have to repeat his wudoo if he does not do
anything to break it [e.g., pass wind, etc.]

Ibn Qudaamah said in al-Mughni (1/217): There are two ways of
making ghusl to purify oneself from janaabah, one of which is sufficient, and the other is
the perfect way. What al-Khiraqi mentions here is the perfect way. Some of our companions
said: the perfect way includes ten things: the niyyah (intention), saying
Bismillah (In the name of Allaah), washing the hands three times,
washing away whatever dirt is there, doing wudoo, pouring water over the head three
times making sure that it reaches the roots, pouring water over the rest of the body,
starting on the right side, rubbing ones body with one’s hand and moving from the
place where one has done ghusl in order to one’s feet. It is mustahabb to make sure that
the water reaches the roots of the hair on one’s head and beard before pouring water over
them. Ahmad said: Ghusl to purify oneself from janaabah should be done in the manner
described in the hadeeth narrated from Aaishah, who said: When the
Messenger of Allaah
(peace and blessings of Allaah be upon him) did ghusl to purify
himself from janaabah (impurity following intercourse), he would start by washing his
hands three times, then he would do wudoo as for prayer, then he would run his
fingers through his hair until he thought the water had reached his scalp, then he would
pour water over his head three times, scooping the water up with both hands, and then he
would wash the rest of his body. (Agreed upon). Maymoonah said: The Messenger
of Allaah
(peace and blessings of Allaah be upon him) did wudoo to purify himself
from janaabah, then he poured water on his hands and washed them two or three times, then
he poured some water from his right hand into his left, and washed his private parts, then
he struck his hand on the floor or wall two or three times, then he rinsed his mouth and
his nose, and washed his face and forearms, then he poured water on his head, then he
washed his entire body, then he moved slightly and washed his feet. Then I brought him a
cloth, but he did not want it, and he started to wipe the water away with his hands.
(Agreed upon). A lot of the requirements (of ghusl) are listed in these two hadeeth.
Beginning on the right is important because the Prophet
(peace and blessings of Allaah be
upon him) liked to always start on the right when purifying himself. According to a
hadeeth narrated from Aaishah, when the Messenger of Allaah
(peace and
blessings of Allaah be upon him) did ghusl to purify himself from janaabah, he would call
for something like a milking-vessel, and he would take some water in his hands, then he
would start with the right side of his head, then the left. Then he would take some water
in his hands and start pouring it over his head. (Agreed upon). With regard to
washing the feet after doing ghusl, there was some dispute as to what Ahmad actually said.
According to one report, he said, I would rather wash them (the feet) after doing
wudoo, because of the hadeeth of Maymoonah. According to another report, he
said, We should act according to the hadeeth of Aaishah, which says that
he did wudoo for prayer before doing ghusl. And Allaah knows best.

He said: If he does ghusl once and makes water reach every part
of his head and body, and does not do wudoo, that should be sufficient if he rinses
his mouth and nose and has the intention to do ghusl and wudoo, but in this case is
not doing that which is better.

What is mentioned here is what is sufficient, but the perfect way is
preferable, which is why he said he is not doing that which is better i.e., if
he does no more than that, this is sufficient even though he is not doing what is perfect
and preferable. The phrase has the intention to do ghusl and wudoo means
that ghusl is sufficient for both if he has the intention for both. This is what was
stated by Ahmad. Another opinion was also narrated from him, which is that ghusl is not
sufficient for wudoo unless he does wudoo either before or after ghusl. This
is also one of the two opinions of al-Shaafai, because the Prophet
(peace and
blessings of Allaah be upon him) did that, and because both janaabah (major impurity) and
hadath (minor impurity) are present, and purification from both is required.

Allaah says (interpretation of the meaning):

approach not al-salaah (the prayer) when you are in a
drunken state until you know (the meaning) of what you utter, nor when you are in a state
of janaabah (i.e., in a state of sexual impurity and have not yet taken a bath) except
when travelling on the road, till you wash your whole body [al-Nisa
4:43]

So the lack of ghusl has been made the factor that prevents a
person from praying, and if a person has done ghusl, he has no reason not to pray. Both
are acts of worship of the same type. In ghusl a lesser type is incorporated in a major
type, as umrah is incorporated in Hajj.

Ibn Abd al-Birr said: The one who does ghusl to purify himself
from janaabah, if he does not do wudoo but he makes water reach every part of his
body, he has done what is required of him, because Allaah has enjoined upon the one who is
in a state of janaabah to do ghusl, not wudoo, when He says (interpretation of the
meaning): if you are in a state of janaabah (i.e., had a sexual
discharge), purify yourself (bathe your whole body. [al-Maaidah 5:6]. This
is the consensus of the scholars and there is no dispute among them; they are agreed that
it is mustahabb to do wudoo before doing ghusl, in emulation of the Messenger of
Allaah
(peace and blessings of Allaah be upon him) and because this reinforces and
perfects ghusl.

And Allaah knows best.