We have a strong city - In opposition to the city of the enemy, which God hath destroyed, Isaiah 25:1-12 (note). See the note there.

Salvation - for walls and bulwarks - חומת וחל chomsoth vachel, walls and redoubts, or the walls and the ditch. חל chel properly signifies the ditch or trench without the wall; see Kimchi. The same rabbin says, This song refers to the time of salvation, i.e., the days of the Messiah.

this song

Isaiah 5:1 Now will I sing to my well beloved a song of my beloved touching his vineyard. My well beloved has a vineyard in a very fruitful hill:

Isaiah 27:1,2 In that day the LORD with his sore and great and strong sword shall punish leviathan the piercing serpent...

Exodus 15:2-21 The LORD is my strength and song, and he is become my salvation: he is my God, and I will prepare him an habitation; my father's God...

Numbers 21:17 Then Israel sang this song, Spring up, O well; sing you to it:

Judges 5:1 Then sang Deborah and Barak the son of Abinoam on that day, saying,

2 Samuel 22:1 And David spoke to the LORD the words of this song in the day that the LORD had delivered him out of the hand of all his enemies...

Jeremiah 33:11 The voice of joy, and the voice of gladness, the voice of the bridegroom, and the voice of the bride, the voice of them that shall say...

Ephesians 5:19,20 Speaking to yourselves in psalms and hymns and spiritual songs, singing and making melody in your heart to the Lord...

Revelation 19:1-7 And after these things I heard a great voice of much people in heaven, saying, Alleluia; Salvation, and glory, and honor, and power...

in the land

Ezra 3:11 And they sang together by course in praising and giving thanks to the LORD; because he is good...

Psalm 137:3,4 For there they that carried us away captive required of us a song; and they that wasted us required of us mirth, saying...

salvation

Isaiah 60:18 Violence shall no more be heard in your land, wasting nor destruction within your borders; but you shall call your walls Salvation...

Isaiah 62:11 Behold, the LORD has proclaimed to the end of the world, Say you to the daughter of Zion, Behold, your salvation comes; behold...

Psalm 31:21 Blessed be the LORD: for he has showed me his marvelous kindness in a strong city.

Psalm 48:12 Walk about Zion, and go round about her: tell the towers thereof.

Zechariah 2:5 For I, said the LORD, will be to her a wall of fire round about, and will be the glory in the middle of her.

Matthew 16:18 And I say also to you, That you are Peter, and on this rock I will build my church; and the gates of hell shall not prevail against it.

Revelation 21:12-22 And had a wall great and high, and had twelve gates, and at the gates twelve angels, and names written thereon...

The Desire of the Soul in Spiritual Darkness
"Tis midnight on the mountains' brown, The cold round moon shines deeply down; Blue roll the waters, blue the sky Spreads like an ocean hung on high, Bespangled with those isles of light, So wildly, spiritually bright; Who ever gazed upon them shining, And turning to earth without repining, Nor wish'd for wings to flee away, And mix with their eternal ray." Even with the most irreligious person, a man farthest from spiritual thought, it seems that there is some power in the grandeur and stillness …
Charles Haddon Spurgeon—Spurgeon's Sermons Volume 1: 1855

"For the Law of the Spirit of Life in Christ Jesus Hath Made Me Free from the Law of Sin and Death. "
Rom. viii. 2.--"For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death." You know there are two principal things in the preceding verse,--the privilege of a Christian, and the property or character of a Christian. He is one that never enters into condemnation; He that believeth shall not perish, John iii. 15. And then he is one that walks not after the flesh, though he be in the flesh, but in a more elevate way above men, after the guiding and leading …
Hugh Binning—The Works of the Rev. Hugh Binning

Condemned to Die
During Paul's final trial before Nero, the emperor had been so strongly impressed with the force of the apostle's words that he deferred the decision of the case, neither acquitting nor condemning the accused servant of God. But the emperor's malice against Paul soon returned. Exasperated by his inability to check the spread of the Christian religion, even in the imperial household, he determined that as soon as a plausible pretext could be found, the apostle should be put to death. Not long afterward …
Ellen Gould White—The Acts of the Apostles