a little late to the game, but hebrews 5:7 immediately popped in my mind when I read this. I'm no Psalms expert, but maybe not all of 119 is from Christs perspective (if any of it is), the BSB breaks it up into sections... idk if this is useful to you but I felt the need to post it.
It is impossible that all of Psalm 119 is from Christ's perspective because in at least 2-3 places the writer expresses sin in themselves.
I have written earlier that the word translated 'Himself' in Hebrews 5:7 could be interpreted as reflexive, i.e. to the One Himself who is able to save, instead of to the one who is able to save Him.
This comes down to whether we believe in the sinlessness and/or diety of Christ or not:
If Christ has no sin He has nothing to be saved from because death is the wage of sin and God is not unjust. Christ lays His own life down and takes it up again Himself. He says so - He raises up the temple of His body; no one takes it from Him.
If Christ is God it is ridiculous to even entertain the idea that He, the one and only Savior, needs to be saved from anything whatsoever.
Even with those things ignored altogether, the passage is speaking specifically & narrowly about God's days manifest in the flesh. Everything He does in those times are for an example to us: demonstrating to us what a righteous life as a human looks like, perfectly. He humbled Himself to take on the form of a man - a perfect man - and lived it all to show us what perfection in the flesh looks like. This does not then mean He Himself needs salvation, but that we who do have need, this is how we ought to conduct ourselves.
Besides these things again - Hebrews speaks of Him offering up prayers and supplications. So where on scripture do we see Christ praying? He Himself taught us to pray on secret, not openly for others to hear or see us. So in those few examples we see of Him praying, they clearly were witnessed - - and knowing that He is not false in what He teaches, the only possible view of those recorded prayers is that He spoke them in the hearing of His disciples for the express purpose of them being recorded, for our benefit.
What benefit? So we would know how to pray, and what righteous prayer looks like. He does snt need to pray aloud for Him to hear Himself ((acknowledging He is God)) or for God to hear Him ((if you deny He is God but agree He is perfect in all His ways)) since God always hears whoever is without sin.
So where do we ever see in scripture Christ praying to be saved? Or anything remotely like it?
Find that and you'll find what Hebrews 5:7 is talking about.