David Expresses His Confidence In God's Protection And Deliverance And Assures Him That He Will Not Be Short On Gratitude (Psalms 54:4-6).
‘Behold, God is my helper,
The Sovereign Lord is of those who uphold my life.
He will requite the evil to my enemies,
Destroy you them in your truth.'
Having prayed to God he is confident of God's help and protection. He sees God as his helper. For had God not anointed him to replace Saul? How then could He not help him to escape from Saul? And he sees Him as the Sovereign Lord (adonai) Who is the Upholder of his life, as One Who is on his side. He is thus confident that God will respond to the evil of his enemies by Himself acting against them, requiting them for what they are doing. And that, having by anointing David demonstrated His favourable attitude towards him, He will be true to His promise so given.
‘With a freewill-offering will I sacrifice to you,
I will give thanks to your name, O YHWH, for it is good,
For he has delivered me out of all trouble,
And my eye has seen (my desire) on my enemies.'
David then promises that he himself will respond in gratitude. He will sacrifice a freewill offering to God, and will give thanks to Him under His covenant Name of YHWH, a Name which he declares to be ‘good' (totally reliable, dependable and trustworthy). Contrast this offering of a sacrifice with Psalms 51:16 where, because he had sinned with a high hand, he knew that no sacrifice would be acceptable until he was sure of forgiveness as a consequence of God's free and unmerited favour.
The goodness of YHWH's Name is especially brought out by the fact that He has delivered David from ‘all trouble', something demonstrated by the fact that David's eye has seen what was necessary for his deliverance on his enemies. (‘Desire' is not there in the Hebrew. David did not desire their discomfiture as such, in the sense of wanting them to suffer and gloating over them. He sought it because it was the only way in which he could be delivered)
Note the fairly unusual use (in this Second Part of Psalms) of the Name YHWH. It is an indication that he is seeing God as having helped him because He is the covenant God.