The Quran is the last Divine Book revealed by Allah Almighty upon his last messenger Muhammad (Peace Be Upon Him).

According to scholars: Quran is the Arabic Speech of Allah Almighty which he revealed to the prophet  Muhammad(PBUH)  through angel jibreel (A.S), and has reached us by Mutawatir (continuous) transmission and a challenge to mankind produced similar to it.

Allah Almighty (God) created Heaven for those people among man king who have a firm belief/Faith  in Allah almighty as Allah mentions in the Quran:

إِنَّ ٱللَّهَ يُدْخِلُ ٱلَّذِينَ ءَامَنُوا۟ وَعَمِلُوا۟ ٱلصَّـٰلِحَـٰتِ جَنَّـٰتٍۢ تَجْرِى مِن تَحْتِهَا ٱلْأَنْهَـٰرُ يُحَلَّوْنَ فِيهَا مِنْ أَسَاوِرَ مِن ذَهَبٍۢ وَلُؤْلُؤًۭا ۖ وَلِبَاسُهُمْ فِيهَا حَرِيرٌۭ

But Allah will surely admit those who Believe/ have Faith and do good into Gardens,(Heaven) under which rivers flow, where they will be adorned with bracelets of gold and pearls, and their clothing will be silk (Al-Hajj:23)

what is Faith?

According to the Hadith of the prophet Muhammad (SAWW)

“It is to believe in Allah, His Angels, His Books, His Messengers, the Last Day, and in the Divine Decree, it is good and it is bad.” (Sunnan al Nasai 4990)

So, along with Good doings/Actions, Believing in God is the first and most important condition to entering Heaven.

Sidra refers to Lotte Tree while Muntaha means the point of end  Thus Sidra is a tree situated on the point where the access to everything ends. which is in the sixth heaven as narrated in the sahih Hadith narrated on the authority of Abdullah (b. Umar) says:

“When the Messenger of Allah (ﷺ) was taken on the Night Journey, he came to Sidrah Al-Muntaha, which is in the sixth heaven. That is where everything that comes up from below ends, and where everything that comes down from above until it is taken from it…..” (sahih Muslim:173)

while according to another narration of Abbas bin Malik it is situated in the seventh heaven, Malik says, “Malik bin Sasaa said that Allah’s Messenger (ﷺ) described to them his Night Journey saying, when I went (over the seventh heaven), there I saw Abraham. Gabriel said (to me), ‘This is your father; pay your greetings to him.’ So I greeted him and he returned the greetings to me and said, ‘You are welcomed, O pious son and pious Prophet.’ Then I was made to ascend to Sidrat-ul-Muntaha (i.e. the Lote Tree of the utmost boundary) Behold! Its fruits were like the jars of Hajr (i.e. a place near Medina) and its leaves were as big as the ears of elephants. Gabriel said, ‘This is the Lote Tree of the utmost boundary.”) (Sahih Bukhari:3887).

A renowned scholar Abu Abdullah al Qurtubi talks about the conflict of the location of Sirda Tul Muntaha according to the above-mentioned narrations,

One who finds water, but is sick, and is afraid that if he uses the water, for Ablution or bath, his sickness will be intensified, In this case, one may perform tayammum (تيمم) (Dry Ablution) with the surface of the earth.
Allah says in the Quran:
If you are sick………………… then make your ablution on clean ground and wipe a part of your face and your hands. Indeed Allah is all-excusing, all-forgiving.” (Al Nisa: 43)

What is Dry Ablution?
To wipe one’s face and hands with the intention of purification by using clean mud sand and stone.

Method of Dry Ablution:
1- Make the intention it is an obligation in dry Ablution.
2-Strike both hands on clean earth or dust.
3- Blow off extra dust.
4- Wipe the entire face once as in Ablution. Make Khilaal the beard.
5- Strike both hands on clean earth for the second time.
6- Blow off extra dust.
7- Wipe the right hand over the left hand including the elbows once.
8- Wipe the left hand over the right hand including the elbows once.