........
c) Why do all the earliest Mosques face Petra? And why does Petra fit the descriptions given in the Qur'an, not Mecca?
Peace be on you.
It was due to calculation methods, IMO.
Magnetic declination was considered to find correct Kaaba direction latter.
Magnetic declination or
variation is the angle on the horizontal plane between magnetic north (the direction the north end of a
compass needle points, corresponding to the direction of the
Earth's magnetic field lines) and
true north (the direction along a
meridian towards the geographic
North Pole). This angle varies depending on position on the Earth's surface, and changes over time.
Example of magnetic declination showing a compass needle with a "positive" (or "easterly") variation from geographic north. Ng is geographic or true north, Nm is magnetic north, and δ is magnetic declination
Ref:
https://en.wikipedia.org/wiki/Magnetic_declination
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According to Needham (1962), changes in magnetic declination were discovered in China around
720 CE when the astronomer Yi-Xing measured magnetic declination (see Figure
14.2b). The compass arrived in Europe some time in the 12th century. Magnets and compasses were discussed in a letter (Epistola) by Petrus Peregrinus written in 1269 (finally printed in 1558). Apparently the idea of declination did not accompany the compass. The deviation of magnetic north from true north was not rediscovered by Europeans until the early 1400s. Europeans began to make systematic measurements of declination in the early 1500s. Magnetic inclination was discovered in the mid-1500s in Europe.
http://magician.ucsd.edu/essentials/WebBookse89.html
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More
https://en.wikipedia.org/wiki/Compass#Muslim_world
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Mere few degrees' difference at original place would create lot of difference near Mecca.
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Kabaa is a buidling in Al-Haram mosque, in Mecca. To Kabaa Muslims face during worship. Muslims do not worship Kabaa:
[Quran 2:145] Verily, We see thee turning thy face often to heaven; surely, then, will We make thee turn to the Qiblah which thou likest. So, turn thy face towards the Sacred Mosque; and wherever you be, turn your faces towards it. And they to whom the Book has been given know that this is the truth from their Lord; and Allah is not unmindful of what they do.
[2:150] And from wheresoever thou comest forth, turn thy face towards the Sacred Mosque; for that is indeed the truth from thy Lord. And Allah is not unmindful of what you do.
[2:151] And from wheresoever thou comest forth, turn thy face towards the Sacred Mosque; and wherever you be, turn your faces towards it that people may have no argument against you, except those who are unjust — so fear them not, but fear Me — and that I may perfect My favour upon you; and that you may be rightly guided.
[3:97] Surely, the first House founded for mankind is that at Becca, abounding in blessings and a guidance for all peoples.
[alislam.org/quran]
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Additional Information:
EXPLANATION ABOUT BLACK STONE AND KABAA
Based on Writting of AHMADIYYA MUSLIM PROMISED MESSIAH MAHDI (on whom be peace)
1= Black stone is there to show as model for a spiritual matter. In Islam, Allah has placed models for important commandments. For example, it is commanded that a believer should offer his or her sacrifice through their self and faculties. And physical sacrifice of animal is token model for this philosophy. Blood and meat of animal do not reach to Allah but only the righteousness of heart reaches..Meaning that a believer should live life as if his or her low self-desires are sacrificed by their own hands. They live according to guidance of God.
2= Parallel to spiritual matters, Allah makes physical matters as model. Kaba is made for that purpose. According to Holy Quran, human is made for worship of God. [it is vast subject: worship indicate recognition, love, fear of losing Him, obedience, paying His and His creation's right, successful life and Hereafter, meeting Lord.]
Worship is of two types:
i-Through humbleness.
ii-Through love and sacrifice.
Explanation:
i- Five daily Islamic Salaat is the worship, in which body stands, bow and prostrate as physical model of the states of soul. Body and soul both offer Salaat. There are prayers in each of these action. In prostration, heart do fall prostrate before Lord. Body and soul affect each other in prayer.
ii- In the second kind of worship through love and sacrifice, body and soul affect each other too. In love, human soul always revolves around beloved and kiss beloved’s place. Similarly, Kaba is physical model for true lovers so that they show their enthusiasm of love. People at Hajj make circuits around kaba in love, they remove their beauties and shave heads, and kiss the black stone as the stone of beloved's place. This physical fire of love creates heat in spiritual love and soul revolve around the Beloved and metaphorically kisses His station.
There is no idol-worship in it. One kisses one's friend's letter too. No Muslim worship Kaba and do not seek anything from blackstone. This is physical model declared by God Himself. We do sajdah (islamic prostration) at earth but we do not worship earth. We kiss blackstone but not for balckstone. Stone is stone it cannot benefit or hurt to anyone. It is Hand of the beloved which pointed that this stone is model of His station.
[Reference: Based on writings of Ahmadiyya Muslim Promised Messiah and Mahdi (on whom be peace) be peace), Ruhani Khazain, vol 23]