Be still and know that I am God, says the LORD

One thing I really enjoy and appreciate about Mendelssohn's Elijah is how the libretto does not only follow the narrative from 1 Kings but also makes allusions to many other Biblical texts.
I give an example below which draws heavily on Psalm 121 and Psalm 46. I also intersperse with the libretto what I believe to be the references for other Biblical allusions.

Elijah has been discouraged in his mission, even to the point of wishing that he would die. To which angels respond:

Lift thine eyes to the mountains, whence cometh help. Thy help cometh from the Lord, the maker of heaven and earth.

Elijah still complains to God: "O Lord, I have labored in vain; yea, I have spent my strength for nought!"

25. Aria: O Rest in the Lord

An Angel

Oh rest in the Lord, wait patiently for Him, and He shall give thee thy heart's desires. Commit thy way unto Him, and trust in Him, and fret not thyself because of evil-doers.

[Psalm 37]

26. Chorus: He that shall endure

Chorus

He that shall endure to the end, shall be saved.

[Matthew 10:22, 24:13]

Elijah then asks that God not hide his face. The LORD then reveals himself,
not in the dramatic (earthquakes, fire,...) but ...

And in that still voice onward came the Lord.

29. Recitative & Chorus: Holy is God

Above Him stood the Seraphim, and one cried to another:

Seraphim

Holy, holy, holy is God the Lord, the Lord Sabaoth! Now His glory hath filled all the earth.

30. Chorus & Recitative: Go, return upon thy way/ I go on my way

Chorus

Go, return upon thy way! For the Lord yet hath left Him seven thousand in Israel, knees which have not bowed to Baal. Go, return upon thy way! Thus the Lord commandeth.

Elijah

I go on my way in the strength of the Lord For Thou art my Lord; and I will suffer for Thy sake. My heart is therefore glad, my glory rejoiceth; and my flesh shall also rest in hope.

31. Arioso: For the mountains

Elijah

For the mountains shall depart, and the hills be removed; but Thy kindness shall not depart from me; neither shall the covenant of Thy peace be removed.