Amplified Bible (AMP)
GOD, my heart is fixed (steadfast, in the confidence of faith); I will sing, yes, I will sing praises, even with my glory [all the faculties and powers of one created in Your image]!
A fixed heart is one which is firm, stable, and stationary. It does not move, waver, or totter through shaking and storm, but continues in confident and steadfast faith.
A fixed heart directs its attention, its gaze upon One knowing that He alone is Perfectly Beautiful.
A fixed heart receives healing from experiences which have damaged it. God "fixes" it!
I will sing Your praises, and my heart will remain fixed!