I know from the sirah of Rasullah that at the beginning of revelation when Jibreel came to Earth and called Rasullah after he (Rasullah) saw him and got frightened, he ran into his house and asked Khadija (RA) to cover him with a blanket.
Now my question is at that time did Khadija (RA) see Jibreel's (AS) original form? Or did anyone among the sahaba or the Muslims see Jibreel's (AS) original form?
No one other the Prophet ﷺ saw Jibrīl in the form that Allah had created him. We know of only two instances when the Prophet ﷺ saw Jibrīl in his true angelic as the Prophet ﷺ reported in this long hadith (partially quoted) narrated in Sahih Muslim on the authority of Masrūq:
إِنَّمَا هُوَ جِبْرِيلُ لَمْ أَرَهُ عَلَى صُورَتِهِ الَّتِي خُلِقَ عَلَيْهَا غَيْرَ هَاتَيْنِ الْمَرَّتَيْنِ رَأَيْتُهُ مُنْهَبِطًا مِنَ السَّمَاءِ سَادًّا عِظَمُ خَلْقِهِ مَا بَيْنَ السَّمَاءِ إِلَى الأَرْضِ
Verily he is Gabriel. I have never seen him in his original form in which he was created except on those two occasions (to which these verses refer); I saw him descending from the heaven and filling (the space) from the sky to the earth with the greatness of his bodily structure.
These two instances are documented in the Qur'an and in the Sunnah:
The first instance was after the initial revelation by Jibrīl and during the period through which revelations were discontinued:
وَلَقَدْ رَآهُ بِالْأُفُقِ الْمُبِينِ
And he has already seen Gabriel in the clear horizon.
The Prophet ﷺ mentioned this instance in a hadith:
وحدثني أبو الطاهر، أخبرنا ابن وهب، قال حدثني يونس، قال قال ابن شهاب أخبرني أبو سلمة بن عبد الرحمن، أن جابر بن عبد الله الأنصاري، - وكان من أصحاب رسول الله صلى الله عليه وسلم كان يحدث قال قال رسول الله صلى الله عليه وسلم وهو يحدث عن فترة الوحى - قال في حديثه: فَبَيْنَا أَنَا أَمْشِي سَمِعْتُ صَوْتًا مِنَ السَّمَاءِ فَرَفَعْتُ رَأْسِي فَإِذَا الْمَلَكُ الَّذِي جَاءَنِي بِحِرَاءٍ جَالِسًا عَلَى كُرْسِيٍّ بَيْنَ السَّمَاءِ وَالأَرْضِ. قال رسول الله صلى الله عليه وسلم: فَجُئِثْتُ مِنْهُ فَرَقًا فَرَجَعْتُ فَقُلْتُ زَمِّلُونِي زَمِّلُونِي . فَدَثَّرُونِي فَأَنْزَلَ اللَّهُ تَبَارَكَ وَتَعَالَى « يَا أَيُّهَا الْمُدَّثِّرُ قُمْ فَأَنْذِرْ وَرَبَّكَ فَكَبِّرْ وَثِيَابَكَ فَطَهِّرْ وَالرُّجْزَ فَاهْجُرْ » وَهِيَ الأَوْثَانُ قَالَ ثُمَّ تَتَابَعَ الْوَحْىُ
Jabir ibn 'Abdullah al-Ansari who was one of the Companions of the Messenger of Allah (ﷺ) reported the Messenger of Allah (ﷺ) told about the intermission of revelation and narrated While I was walking I heard a voice from the sky, and raising my head I saw the angel who had come to me in Hira', sitting on a Throne between heaven and earth I was terror-stricken on that account and came back (to my family) and said: "Wrap me up, wrap me up! So they wrapped me up, and the Blessed and Most Exalted Allah sent down: 'You who are shrouded, arise and deliver warning, your Lord magnify, your clothes cleanse, and defilement shun,' and defilement means idols; and then the revelation was followed continuously."
The second instance was during al-Mi'rāj (ascension into heaven):
وَلَقَدْ رَآهُ نَزْلَةً أُخْرَىٰ عِندَ سِدْرَةِ الْمُنتَهَىٰ
And he certainly saw him in another descent at the Lote Tree of the Utmost Boundary —
Other than the two instances mentioned above, Jibrīl used to take a human form when talking to the Prophet ﷺ or his companions, e.g., that of the companion Dihyah al-Kalbi.
The below Hadith states that some of the Sahaba at a later stage saw Gabriel (Jibreel) in the human form:
حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا إِسْمَاعِيلُ بْنُ إِبْرَاهِيمَ، أَخْبَرَنَا أَبُو حَيَّانَ التَّيْمِيُّ، عَنْ أَبِي زُرْعَةَ، عَنْ أَبِي هُرَيْرَةَ، قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم بَارِزًا يَوْمًا لِلنَّاسِ، فَأَتَاهُ جِبْرِيلُ فَقَالَ مَا الإِيمَانُ قَالَ " الإِيمَانُ أَنْ تُؤْمِنَ بِاللَّهِ وَمَلاَئِكَتِهِ وَبِلِقَائِهِ وَرُسُلِهِ، وَتُؤْمِنَ بِالْبَعْثِ ". قَالَ مَا الإِسْلاَمُ قَالَ " الإِسْلاَمُ أَنْ تَعْبُدَ اللَّهَ وَلاَ تُشْرِكَ بِهِ، وَتُقِيمَ الصَّلاَةَ، وَتُؤَدِّيَ الزَّكَاةَ الْمَفْرُوضَةَ، وَتَصُومَ رَمَضَانَ ". قَالَ مَا الإِحْسَانُ قَالَ " أَنْ تَعْبُدَ اللَّهَ كَأَنَّكَ تَرَاهُ، فَإِنْ لَمْ تَكُنْ تَرَاهُ فَإِنَّهُ يَرَاكَ ". قَالَ مَتَى السَّاعَةُ قَالَ " مَا الْمَسْئُولُ عَنْهَا بِأَعْلَمَ مِنَ السَّائِلِ، وَسَأُخْبِرُكَ عَنْ أَشْرَاطِهَا إِذَا وَلَدَتِ الأَمَةُ رَبَّهَا، وَإِذَا تَطَاوَلَ رُعَاةُ الإِبِلِ الْبُهْمُ فِي الْبُنْيَانِ، فِي خَمْسٍ لاَ يَعْلَمُهُنَّ إِلاَّ اللَّهُ ". ثُمَّ تَلاَ النَّبِيُّ صلى الله عليه وسلم {إِنَّ اللَّهَ عِنْدَهُ عِلْمُ السَّاعَةِ} الآيَةَ. ثُمَّ أَدْبَرَ فَقَالَ " رُدُّوهُ ". فَلَمْ يَرَوْا شَيْئًا. فَقَالَ " هَذَا جِبْرِيلُ جَاءَ يُعَلِّمُ النَّاسَ دِينَهُمْ ". قَالَ أَبُو عَبْدِ اللَّهِ جَعَلَ ذَلِكَ كُلَّهُ مِنَ الإِيمَانِ.
Narrated Abu Huraira:
One day while the Prophet (ﷺ) was sitting in the company of some people, (The angel) Gabriel came and asked, "What is faith?" Allah's Messenger (ﷺ) replied, 'Faith is to believe in Allah, His angels, (the) meeting with Him, His Apostles, and to believe in Resurrection." Then he further asked, "What is Islam?" Allah's Messenger (ﷺ) replied, "To worship Allah Alone and none else, to offer prayers perfectly to pay the compulsory charity (Zakat) and to observe fasts during the month of Ramadan." Then he further asked, "What is Ihsan (perfection)?" Allah's Messenger (ﷺ) replied, "To worship Allah as if you see Him, and if you cannot achieve this state of devotion then you must consider that He is looking at you." Then he further asked, "When will the Hour be established?" Allah's Messenger (ﷺ) replied, "The answerer has no better knowledge than the questioner. But I will inform you about its portents.
When a slave (lady) gives birth to her master.
When the shepherds of black camels start boasting and competing with others in the construction of higher buildings. And the Hour is one of five things which nobody knows except Allah.
The Prophet (ﷺ) then recited: "Verily, with Allah (Alone) is the knowledge of the Hour--." (Quran 31:34) Then that man (Gabriel) left and the Prophet (ﷺ) asked his companions to call him back, but they could not see him. Then the Prophet (ﷺ) said, "That was Gabriel who came to teach the people their religion." Abu 'Abdullah said: He (the Prophet) considered all that as a part of faith.
