After Rasulullah (sallallahu ‘alaihi wasallam) and Hazrat Abu Bakr (radhiyallahu ‘anhu) entered the Cave of Thowr, Allah Ta‘ala caused a spider to spin a web across the entrance of the cave.

لو دخل هنا لم يكن نسيج العنكبوت على بابه

“Had he (sallallahu ‘alaihi wasallam) entered this cave, the spider’s web would not be covering the entrance.”

While Rasulullah (sallallahu ‘alaihi wasallam) was taking refuge in the Cave of Thowr, through the command of Allah Ta‘ala, a tree miraculously grew in front of him. A pair of wild doves then came and laid their eggs in a nest in the tree. When the disbelievers were searching for Rasulullah (sallallahu ‘alaihi wasallam), they came across the cave, but when they caught sight of the doves’ nests in the tree, they turned around and left. Rasulullah (sallallahu ‘alaihi wasallam) said, “Allah Ta‘ala made them turn away from us by means of these doves.”

Hazrat Abu Bakr (radhiyallahu ‘anhu) mentions:

When Rasulullah (sallallahu ‘alaihi wasallam) and I were in the cave, and the Quraish continued searching for us, till they reached close to the mouth of the cave, I addressed Rasulullah (sallallahu ‘alaihi wasallam) saying, “O Rasul of Allah (sallallahu ‘alaihi wasallam)! If any one of them has to lower his gaze, he will certainly see us!” Rasulullah (sallallahu ‘alaihi wasallam) replied:

ما ظنك يا أبا بكر باثنين اللّٰه ثالثهما

O Abu Bakr! What do you think regarding two such people who the third with them is Allah?

In other words, we are not alone. The third One with us is Allah who will safeguard us from their evil.

When Rasulullah (sallallahu ‘alaihi wasallam) noticed the worry and concern of Hazrat Abu Bakr (radhiyallahu ‘anhu), he said to him:

لَا تَحْزَنْ إِنَّ اللهَ مَعَنَا

Do not worry! Certainly Allah is with us.

Rasulullah (sallallahu ‘alaihi wasallam) also made special du‘aa for Hazrat Abu Bakr to be overcome by tranquility and serenity, after which a unique form of tranquility and serenity from the side of Allah Ta‘ala descended over them. In this regard, Allah Ta‘ala states in the Qur’aan Majeed:

اِذۡ ہُمَا فِی الۡغَارِ اِذۡ یَقُوۡلُ لِصَاحِبِہٖ لَا تَحۡزَنۡ اِنَّ اللّٰہَ مَعَنَا ۚ فَاَنۡزَلَ اللّٰہُ سَکِیۡنَتَہٗ عَلَیۡہِ وَ اَیَّدَہٗ  بِجُنُوۡدٍ لَّمۡ تَرَوۡہَا وَ جَعَلَ کَلِمَۃَ  الَّذِیۡنَ کَفَرُوا السُّفۡلٰی ؕ وَ کَلِمَۃُ  اللّٰہِ ہِیَ الۡعُلۡیَا ؕ وَ اللّٰہُ  عَزِیۡزٌ  حَکِیۡمٌ  ﴿۴۰﴾

“When they two were in the cave, and he (Rasulullah [sallallahu ‘alaihi wasallam]) was saying to his companion (Hazrat Abu Bakr [radhiyallahu ‘anhu]), “Do not worry. Allah is surely with us.” So, Allah caused His tranquility to descend upon him (Rasulullah [sallallahu ‘alaihi wasallam] and Hazrat Abu Bakr [radhiyallahu ‘anhu]), and supported him (Rasulullah [sallallahu ‘alaihi wasallam]) with troops (angels) that you did not see, and He caused the word of the disbelievers to be the lowest, and the word of Allah is always the highest, and Allah is All-Mighty, All-Wise.” (Surah Taubah v. 40)

(Extracted from Seeratul Mustafa 1/365-367)