‘YHWH also will be a high tower for the oppressed,
A high tower in times of trouble;
And those who know your name will put their trust in you;
For you, YHWH, have not forsaken those who seek you.'
But it is not only the Davidic king who enjoys God's protection, it is he and all God's true people. God protects all who, because they are righteous and trust in Him, are oppressed by the unrighteous, and He will be a fortress tower on their behalf, into which they can enter and be safe. While they may be laid siege to, or may be bombarded, they will be totally secure. Those who know Him for what He is will put their trust in Him, knowing that He will never forsake those who seek Him. They know by faith that he is totally reliable, and that they can shelter securely in His hands.
‘A high tower.' A regular description of YHWH's protecting hand (e.g. Psalms 18:2; Psalms 144:2; see also Proverbs 18:10)
‘In times of trouble.' That is, in the extremity of trouble when all hope of deliverance seems to be cut off.