Psalm 9:9 (ESV) … “The Lord is a stronghold for the oppressed, a stronghold in times of trouble.”
The psalmist describes Yahweh as a place of refuge for the oppressed. The Hebrew word used here, misgav, describes high walls or a rocky fortress (Isa 25:12; 33:16). When applied to Yahweh, it emphasizes the stable protection He provides for those in need (Psa 62:6–8).
The word for “refuge” is sometimes rendered “a high tower.” David was no stranger to trouble. He had spent most of his youth and early manhood hiding in the hills, forests, wastelands, and foreign countries from Saul’s executioners. Often he had longed for a high tower, a place of security into which he could run and hide, secure from his foes. He found such a refuge in the Lord. The persecuted tribulation saints (those who obey the Lord’s instructions in Matthew 24) will find just such a high tower in the Lord.
 Barry, J. D., Mangum, D., Brown, D. R., Heiser, M. S., Custis, M., Ritzema, E., Whitehead, M. M., Grigoni, M. R., & Bomar, D. (2012, 2016). Faithlife Study Bible (Ps 9:9). Lexham Press.  Phillips, J. (2009). Exploring Psalms 1–88: An Expository Commentary (Vol. 1, Ps 9:9–10). Kregel Publications; WORDsearch Corp.