What is the historical significance of Jabal Thawr in the Hijrah to Madinah?

The Background of the Hijrah (Migration):
During the first three years of the Prophetic mission there was no opposition to Islam by the idolaters of Makkah. This was because its preaching was private and confined to a restricted circle of the Prophet’s (peace be upon him) relatives and friends. First signs of opposition appeared when the Holy Prophet (peace be upon him) started public preaching. And this was especially when he entered the house of Al-Arqam, which had become the centre of his missionary activities. Their opposition was, at first, expressed in mild incivilities mixed with curiosity. They mostly taunted the Prophet (peace be upon him). “There goes the son of Abdullah”, they would remark when the Holy Prophet (peace be upon him) happened to pass by them, “who brings news from the Heaven”. But when the Holy Prophet (peace be upon him) began to denounce their idol-worship and warned them of the terrible consequences of their disbelief, their opposition became more hostile and violent. Their abuses changed to persecution.

The Holy Prophet (peace be upon him) was subjected to increasing insults and rude treatment. When he happened to pass in a street or was at prayer, rubbish and sweepings were dumped on his head. Thorns were spread in his path. The Muslim Community lost their social status; even worse, their rights. The first and the most to suffer at the hands of the Quraish were the converted slaves. They were subjected to all kinds of tortures. They were beaten, roasted on scorching sands of the midday sun of the Arabian noon, and even butchered in cold blood. Even in normal times, Arabia is a hard land for weaker sections of the society such as the slaves. But during the advent of Islam, their lot was harder still. Such is the picture of early Islam.

The Call for Migration:
Hostilities by the Quraish intensified after the successful migrations to Abyssinia. The Prophet (peace be upon him) thus decided to take refuge in the city of Yathrib from the fury of his Makkahn enemies. In the tribalistic society of ancient Arabia it was not easy for a man to shift his residence from one city to another. He could be killed by any man for transferring his allegiance. This danger faced the Muslims of Makkah when they migrated from their native city to Yathrib or Madinah as it should now be called. They wanted to migrate because of the Quraishite persecutions. And also because the Prophet (peace be upon him) said so. Nevertheless, they left Makkah in parties of twos and threes till only the Holy Prophet (peace be upon him), Hazrat Abu Bakr and Hazrat Ali (may God be pleased with them) and their families were left behind.

In all nearly a hundred families made Hijrah to Madinah and thus came to be known as the Muhajreen or the Emigrants. The Quraish had already got the intelligence of the Prophet’s (peace be upon him) meeting with the Yathribites. But when they saw the houses and even the whole quarters of the Muslims deserted by their dwellers, their suspicions were confirmed and their apprehensions aroused. Their leaders met in the council hall, the Dar-un-Nadwa, in the Kaaba. Abu Jahal proposed that the Prophet (peace be upon him) must be killed. The suggestion was readily accepted and the gang of assassins, headed by Abu Jahal, chased the two after an unexpected delay at the Prophet’s (peace be upon him) house, where Hazrat Ali (may God be pleased with him) was found sleeping in the bed of the Prophet (peace be upon him). The Prophet (peace be upon him), who had anticipated such a move from the Quraish, was promptly informed of their evil design.
After giving final instructions to Hazrat Ali (may God be pleased with him), he left his house along with Hazrat Abu Bakr (may God be pleased with him) and went to the south of Makkah.

The Prophet (peace be upon him) and his companion (may God be pleased with him) hid themselves inside a cave in the Mount of Thawr. There they stayed for three days and three nights. Abu Jahal dispatched mounted men in all directions to apprehend the Prophet (peace be upon him) dead or alive. For three days they vigorously searched for both of them, but at last they despaired of it and slackened their efforts. When informed of it, the Holy Prophet (peace be upon him) and Hazrat Abu Bakr (may God be pleased with him) departed to Madinah on two camels. By forced marches, they covered the distance between the two cities in half the usual time, and reached the village of Quba on 22nd September, 622. This was the Prophet’s Hijrah, which opened a new chapter in the history of Islam.

The Stay at Jabal Thawr:
Throughout the length of this journey, Hazrat Abu Bakr (may God be pleased with him) displayed signs of true loyalty. When they entered the Cave of Thawr, he was the one who entered first. He made sure that the cave was entirely safe for the Prophet (peace be upon him) to enter and stay. Whilst inside the cave, he welcomed the Prophet (peace be upon him) to nap in his lap. As the Prophet (peace be upon him) was thus asleep, he got stung by some venomous insect. But he endured till his teardrops awakened the Prophet (peace be upon him). Thus he demonstrated that he was indeed the right choice of the Prophet (peace be upon him). Whereas his efforts are worthy of our praise, the efforts of his family cannot be ignored.

When freed, a slave became the Maula or client of the family to which he owed his freedom. He reciprocated the generosity by tending their sheep. Or he would carry out some other chores of that family. Amir bin Fuhayrah (may God be pleased with him) was one such man. He was a maula of Hazrat Abu Bakr's (may God be pleased with him) clan and worked as a shepherd. The route that his master and the Prophet (peace be upon him) took to reach Jabal Thawr was filled with camel tracks. He followed the two with his flock of sheep thus eliminating those tracks. Furthermore, he stayed near the Mount Thawr and furnished them with fresh milk from time to time.

As regards the camels, Hazrat Abu Bakr’s son, Abdullah bin Abi Bakr (may God be pleased with him) brought them back to Makkah once their riders were safely dropped at their destination. He was further instructed to keep both ears open for intrigues and to report back to the dwellers of the cave. Amir bin Fuhayrah (may God be pleased with him) covered Abdullah’s tracks as well. When Hazrat Abu Bakr’s (may God be pleased with him) returned the second night, he was accompanied by his sister and Hazrat Abu Bakr’s (may God be pleased with him) daughter; Hazrat Asma (may God be pleased with her). She supplied them with food.

Still, some of their pursuers reached the cave on the third day. This was a critical moment. And when the protection rendered to them by the cave seemed hopeless, Hazrat Abu Bakr (may God be pleased with him) panicked. The Prophet (peace be upon him) comforted him with these legendary words. The hadith, as narrated by Hazrat Abu Bakr (may God be pleased with him) goes:

I said to the Prophet (peace be upon him) while I was in the Cave. "If any of them should look under his feet, he would see us." He said, "O Abu Bakr! What do you think of two (persons) the third of whom is Allah?"
Reference : Sahih al-Bukhari H # 3653

Perhaps it was a spider that weaved a web at the entrance or the angels who covered the mouth of the cave with their wings, God knows best. Details are debatable and such ahadith are considered authentic (hassan) by some scholars and dhaeef by others.

The Conclusion:
Thus concluded the Prophet’s (peace be upon him) sojourn at Mount Thawr. The Almighty thus summarizes the entire episode in the Quran:

“If ye help not (your Leader) (it is no matter): for Allah did indeed help him: when the unbelievers drove him out: he had no more than one companion: they two were in the cave and he said to his companion "have no fear for Allah is with us": then Allah sent down his peace upon him and strengthened him with forces which ye saw not and humbled to the depths the word of the unbelievers. But the word of Allah is exalted to the heights: for Allah is Exalted in might, Wise.” {Surah at-Tawbah, Ayat 40}