What is the meaning when Jesus said "I commend my spirit" in Luke 23:46? Then Jesus called out in a loud voice, “Father, into Your hands I commit My Spirit.” And when He had said this, He breathed His last.(Luke 23:46)


The Catholic Church teaches the Jesus Christ was True God and True Man and was given like the rest of mankind a "rational soul and human will".

This can be seen in the Agony in the Garden when Jesus said in Luke gospel,


  “Father, if You are willing, take this cup from Me. Yet not My will, but Yours be done.”(Luke 22:42)


My simple question is from Catholic teaching and biblical explanation what is the spirit that Jesus commended?

Is it his human soul or the Spirit of Christ?
In his response to someone who claimed that Jesus had a 'divine soul' (sic) William Huntington wrote a piece (it is only 28 pages in booklet form) which he titled The Soul of Christ in which he thoroughly refutes the stated claim and proves that Christ's soul is human.
I cannot find exactly the words to answer your question - 'into your hands I commit my spirit' - but the following is pertinent and, I believe, gives an indication of an answer :

Thus I have proved that the phrase 'myself' sometimes signifies Christ's Godhead abstractly considered : 'I lay down my life of myself', and sometimes it signifies his human nature only : 'See that it is I myself, for a spirit hath not flesh and bones, as ye see me have.
There is an 'I myself' in Christ, that hath been seen and handled, and there is a divine 'I myself' that dwells in the light to which no man can approach, whom no eye hath seen nor can see.

The Soul of Christ, page 8, published by the Huntingtonian Press, 1998.
From these quotes it is clear that Christ's words can sometimes indicate that he speaks of his own spirit associated with his own human soul, and at times he refers to his own spirit associated with his own Deity.
For the union of Christ's divine nature and his human nature is not a mingling of natures (for that cannot be, they are different things). The natures remain distinct, but they are united - in his Person.
But he may also - as in the case in question - refer to the person of the Divine Spirit which is in a perfect unity with himself. And it is sometimes impossible to tell whether he speaks of his own spirit or if he speaks of the Divine Person of the spirit.
Nor is this to be seen as a difficulty for such is the perfection of unity within the Deity, that one is as the other.
The same is true of one who is born of Spirit. Within his own soul, there dwells the Holy Spirit in union with his own created spirit. If he is moved of the Spirit, it is his own spirit that is moved.
In such a holy and spiritual union, who can tell exactly the movings of the persons involved ?
And, indeed, do we have to tell ?