Who are these which are arrayed in white robes, and where did they come from?@Revelation 7:13
Isaac Watts (1674–1748)

Isaac Watts, Hymns and Spiritual Songs 1707. The original version has gone through considerable alteration in the Scottish Translations and Paraphrases, and Hymns Ancient and Modern, among others.

Elim (Greatorex) Henry W. Greatorex, 1849 (🔊 pdf nwc).

When Duncan Matheson, the Scotch evangelist, was working in the Crimea, he was returning one night, worn out, from Sebastopol to the old stable at Balaclava where he lodged. He was trudging through mud knee-deep, and the siege seemed no nearer to an end, yet above the stars were looking down from the clear sky. He began to sing, ‘How bright those glorious spirits shine.’ Next day he found a soldier shivering under a verandah, with his bare toes showing through his worn-out boots. Matheson gave him half a sovereign to buy a new pair. The soldier thanked him. ‘I am not what I was yesterday. Last night as I was thinking of our miserable condition, I grew tired of life, and said to myself, I can bear this no longer, and may as well put an end to it. So I took my musket and went down yonder in a desperate state, about eleven o’clock; but as I got round the point, I heard some person singing, How bright those glorious spirits shine; and I remembered the old school and the Sabbath school where we used to sing it. I felt ashamed of being so cowardly, and said, Here is some one as badly off as myself, and yet he is not giving in. I felt, too, he had something to make him happy which I had not, but I began to hope I, too, might get the same happiness. I returned to my tent, and to-day I am resolved to seek the one thing.’ ‘Do you know who the singer was?’ I asked the missionary. ‘No,’ was the reply. ‘Well,’ said Mr. Matheson, ‘it was I.’ Tears rushed into the soldier’s eyes, and handing back the half-sovereign, he said, ‘Never, sir, can I take it from you after what you have been the means of doing for me.’

Telford, pp. 410–11

How bright these glorious spirits shine!
Whence all their white array?
How came they to the blissful seats
Of everlasting day?

Lo! these are they from sufferings great
Who came to realms of light;
And in the blood of Christ have washed
Those robes which shine so bright.

Now with triumphal palms they stand
Before the throne on high,
And serve the God they love amidst
The glories of the sky.

His presence fills each heart with joy,
Tunes every mouth to sing:
By day, by night, the sacred courts
With glad hosannas ring.

Hunger and thirst are felt no more,
Nor suns with scorching ray;
God is their sun, whose cheering beams
Diffuse eternal day.

The Lamb, which dwells amidst the throne
Shall over them still preside,
Feed them with nourishment divine,
And all their footsteps guide.

Midst pastures green He’ll lead His flock
Where living streams appear;
And God the Lord from every eye
Shall wipe off every tear.

To Father, Son and Holy Ghost,
The God whom we adore,
Be glory, as it was, is now,
And shall be evermore.