Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
According to the Quran, the “Holy Spirit” (Ar-Ruh al-Qudus) is Jibreel (peace be upon him).
Answering your question, the Fatwa Center at Islam Q and A, states:
The ‘Hopy Spirit’ in the Quran
The “Holy Spirit” (Ar-Ruh al-Qudus) is Jibreel (peace be upon him). Shaykh al-Shanqeeti said: “The words of Allah (interpretation of the meaning), ‘and (We) supported him with Ar-Ruh al-Qudus’ (al-Baqarah 2:87) refer to Jibreel according to the most sound view. This is indicated by the words (interpretation of the meaning): ‘Which the trustworthy Rooh has brought down’ (al-Shu’ara’ 26:193) and ‘then We sent to her our Rooh’ (Maryam 19:17).”
Ibn Abi Hatim narrated from Ahmad ibn Sinan… Abu’l-Za’ra’ told us: ‘Abd-Allah said: Ar-Ruh al-Qudus (“the Holy Spirit”) is Jibreel, then he said: something similar was narrated from Muhammad ibn Ka’b al-Qurazi, Qutadah, ‘Atiyah al-‘Awfi, al-Saddi and al-Rabi’ ibn Anas.
The ‘Holy Spirit’ in the Sunnah
This view is supported by the above and by the report narrated by the two Shaykhs (al-Bukhaari and Muslim) with their isnads from Abu Salamah ibn ‘Abd al-Rahman ibn ‘Awf, that he heard Hasan ibn Thabit al-Ansari asking Abu Hurayrah to bear witness, “I ask you by Allah, did you hear the Messenger of Allah (peace and blessings of Allah be upon him) say, ‘O Hasan, respond on behalf of the Messenger of Allah. O Allah, support him with Ar-Ruh al-Qudus’?” Abu Hurayrah said, “Yes.” (Al-Tafsir al-Masbur by Dr. Hikmat Basheer, 1/192-193)
Ibn Taymiyyah said:
“The majority of scholars said that this refers to Jibreel (peace be upon him), and that Allah called him al-Ruh al-Amin, Ar-Ruh al-Qudus and Jibreel.” (Daqa’iq al-Tafsir, part 1, p. 310)
He wrote an entire chapter on that and said:
“Chapter on the meaning of Ar-Ruh al-Qudus:
Allah said:
“O ‘Eesa (Jesus), son of Maryam (Mary)! Remember My Favour to you and to your mother when I supported you with Rooh ul Qudus (Jibreel (Gabriel))…” (Al-Maa’idah 5:110)
Allah supported the Messiah (peace be upon him) with Ar-Ruh al-Qudus as He mentions in this aayah. In al-Baqarah Allah says (interpretation of the meaning):
“And We gave ‘Eesa (Jesus), the son of Maryam (Mary), clear signs and supported him with Rooh-ul-Qudus (Jibreel (Gabriel).) (Al-Baqarah 2:87)
“Those Messengers! We preferred some of them to others; to some of them Allâh spoke (directly); others He raised to degrees (of honour); and to ‘Eesa (Jesus), the son of Maryam (Mary), We gave clear proofs and evidences, and supported him with Ruh al-Qudus (Jibreel (Gabriel))” (Al-Baqarah 2:253)
This is not limited only to the Messiah; others were also supported in this way. The scholars mentioned that Dawud said, “Do not stop supporting me with Ar-Ruh al-Qudus.” And our Prophet (peace and blessings of Allah be upon him) said to Hasan ibn Thabit, “O Allah, support him with Ar-Ruh al-Qudus.” According to another report: “Ar-Ruh al-Qudus will be with you so long as you are defending His Prophet.” Both versions are narrated in al-Sahih.
The ‘Holy Spirit’ in Christianity
According to the Christians, the “Holy Spirit” dwelt in the Disciples, and according to them the “Holy Spirit” is something experienced by all of the Prophets. But Allah says in al-Nahl:
“Say (O Muhammad) Rooh ul Qudus (Jibreel (Gabriel)) has brought it (the Quran) down from your Lord with truth, that it may make firm and strengthen (the Faith of) those who believe, and as a guidance and glad tidings to those who have submitted (to Allah as Muslims).” (An-Nahl 16:102)
“Which the trustworthy Rooh (Jibreel (Gabriel)) has brought down upon your heart (O Muhammad).” (Al-Shu’ara’ 26:193)
“Whoever is an enemy to Jibreel (Gabriel) (let him die in his fury), for indeed he has brought it (this Qur’aan) down to your heart.” (Al-Baqarah 2:97)
So it is clear that Ar-Ruh al-Qudus here refers to Jibreel… No one suggests that Ar-Ruh al-Qudus means the life of Allah; nor is this indicated by the wording and this phrase is never used in that sense.” (Daqaa’iq al-Tafseer, part 2, p. 92)
Almighty Allah knows best.
Source: Islam Q&A.