The subject term is a Qur'aanic word الروح. It being a divine term, it would be appropriate for us to seek its meaning from the Holy Book itself. So, let us study the Verses, in which the word occurs, in their chronological order:
Verse 16:2
'HE sends down the angels with the essence or spirit (الروح) of His Command upon whomsoever He wishes from amongst His subjects to warn, "There is indeed none worthy of worship but Me! So, fear Me."'
It is the reality of life that none is worthy of worship but Allah! One that realizes this (through the angels and the spirit sent down by Allah), attains to salvation; and one that doesn't, fails – miserably!
Verse 17:85
'And they ask you about الروح. Say, "الروح concerns my Lord's command! And you have not been given of the knowledge but little!"'
This Verse makes it abundantly clear that human knowledge about الروح is limited.'
Verse 26:193
'The trustworthy الروح has come down with it (the Qur'aan).'
Here, الروح has been described as trustworthy. In other words, the Qur'aan is trustworthy! The الروح, that is Allah's Command that accompanied the Qur'aan, protects it continuously from human interference/pollution. It remains divine as ever.
Verse 40:15
'Raiser of the ranks, Possessor of the throne (of Power), casts الروح of His Command upon whomsoever, He wishes, of His subjects to warn of the Day of the Meeting (with Him).'
The الروح here is the essence, the spirit, of the divine Command as seen in Verse 16:2 above. The one who is endowed with this Essence is the real believer!
Verse 70:4
'The angels and الروح ascend to Him in a day the count of which is fifty thousand years!'
In Chapter 70, it is also mentioned that time is relative. What seems far off to us, humans, is very near in divine knowledge! The theory of relativity, that was propounded by Einstein during the last (20th) century was described as a fact of life, way back in the 7th century, in the Qur'aan! And, in some quarters, الروح mentioned in this Verse is said to be angel Gabriel. But let us stick to what Allah says, that الروح is the essence, the spirit, of His Command.
Verse 78:38
'The Day when الروح and the angels all stand in line and utter no word except as permitted by the Gracious One! And they will say nothing but the Truth.'
The الروح is given here a distinct identity, along with the angels. They will all speak only the truth when asked.
Verse 97:4
'The angels and الروح descend in it (the Night of Allah's Decree) by their Lord's Will, for every divine Command.'
Here, الروح is again associated with the angels.
So, Ar-Rooh is the Essence, or Spirit, of divine Command. It moves with the angels on their divine errands, as mentioned in the Verses above, perhaps ensuring their correct execution. It is operated by itself, without the angels, also. But, we, humans, have been endowed with very little knowledge about it, and about other things as well.
1st July 2022.