Psalms 44 as well as 48 (as well as every other O.T. prophecy), was a prophecy concerning the Christians and Christ's Coming, which was of course, only fulfilled in Christ and His Christian witnesses, whom, as Paul also confirmed;
(Psa 44:22) Yea, for thy sake are we killed all the day long; We are accounted as sheep for the slaughter.
Fulfilled in Christians;
(Rom 8:35) Who shall separate us from the love of Christ? shall tribulation, or anguish, or persecution, or famine, or nakedness, or peril, or sword?
(Rom 8:36) Even as it is written, For thy sake we are killed all the day long; We were accounted as sheep for the slaughter.
(Rom 8:37) Nay, in all these things we are more than conquerors through him that loved us.
(Rom 8:38) For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers,
(Rom 8:39) nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord.
Likewise, Psa 48 only finds it's fulfillment in Christ in the N.T.
It is all about the Beautiful City of the Great King.
This is only Christians in Christ, as referred to in the N.T.
Heb 12:22 but ye are come unto mount Zion, and unto the city of the living God, the heavenly Jerusalem, and to innumerable hosts of angels,
Heb 12:23 to the general assembly and church of the firstborn who are enrolled in heaven, and to God the Judge of all, and to the spirits of just men made perfect,
Heb 12:24 and to Jesus the mediator of a new covenant, and to the blood of sprinkling that speaketh better than that of Abel.
Of whom are true New Jerusalem Christians are born;
(Gal 4:26) But the Jerusalem that is above is free, which is our mother.
(Mat 5:35) nor by the earth, for it is the footstool of his feet; nor by Jerusalem, for it is the city of the great King.
She is Christ's Wife;
(Rom 7:4) Wherefore, my brethren, ye also are become dead to the law by the body of Christ; that ye should be married to another, even to him who is raised from the dead, that we should bring forth fruit unto God. (fruit = sons of God, His and her children)
(Rev 21:9) ...Come hither, I will shew thee the bride, the Lamb's wife.
This is how we appear to Him :)
(Rev 21:2) And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband.
(Rev 12:1) And there appeared a great wonder in heaven; a woman clothed with the sun, and the moon under her feet, and upon her head a crown of twelve stars:
(Rev 12:2) And she being with child cried, travailing in birth, and pained to be delivered.
We are "pregnant" containing within us His Son, even Christ in us is being 'formed' as a result of conceiving from this Marriage of us with Jesus the Bridegroom.
It is how Christ "COMES";
(Joh 16:18) They said therefore, What is this that he saith, A little while? we cannot tell what he saith.
(Joh 16:21) A woman when she is in travail hath sorrow, because her hour is come: but as soon as she is delivered of the child, she remembereth no more the anguish, for joy that a man is born into the world.
Praise Jesus!
PS beware of Jewish "futurism" fables which rob the Gospel of this meaning, putting it off into some future age amongst godless anti-christ Jews.
(Tit 1:14)
(Not giving heed to Jewish fables, and commandments of men, that turn from the truth.)