Spirit of Father or Spirit of Son
Holy Spirit is the upmost gift of our Heavenly Father that we receive by the ultimate sacrifice of His only begotten Son Jesus Christ, When we talk about Holy Spirit, the first thing that comes into our mind that He is the second person in the Trinity God, but we can see in the Bible that the Son Jesus Christ calling the Holy Spirit as "Spirit of Father" - 17.Beware of men, for they will deliver you over to courts and flog you in their synagogues, 18.and you will be dragged before governors and kings for my sake, to bear witness before them and the Gentiles. 19.When they deliver you over, do not be anxious how you are to speak or what you are to say, for what you are to say will be given to you in that hour. 20.For it is not you who speak, but the Spirit of your Father speaking through you - Matthew 10:17-20
And at the time, our Heavenly Father is calling the Holy Spirit as "Spirit of Son", why Christ is calling the Holy Spirit as "Spirit of Father" and the Father calling Him as "Spirit of Son"? - 6.And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!” 7.So you are no longer a slave, but a son, and if a son, then an heir through God - Galatians 4:6-7
Abraham's Explanation
When God visited Abraham, He prayed to God to have a bread, and God agreed for what Abraham had asked - 1.And the Lord appeared unto him in the plains of Mamre: and he sat in the tent door in the heat of the day; 2.And he lift up his eyes and looked, and, lo, three men stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground, 3.And said, My Lord, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant: 4.Let a little water, I pray you, be fetched, and wash your feet, and rest yourselves under the tree: 5.And I will fetch a morsel of bread, and comfort ye your hearts; after that ye shall pass on: for therefore are ye come to your servant. And they said, So do, as thou hast said. 6.So Abraham hurried into the tent to Sarah. Quick, he said, get three seahs of the finest flour and knead it and bake some bread. 7.Then he ran to the herd and selected a choice, tender calf and gave it to a servant, who hurried to prepare it - Genesis 18:6-7
But instead of Bread, Abraham served three other rich food that is butter, milk, and the calf - And he took butter, and milk, and the calf which he had dressed, and set it before them; and he stood by them under the tree, and they did eat - Genesis 18:8
So, according to Abraham, Bread means, its a combination of three rich food that is Butter, Milk and Calf, here the Calf is representing the Word[The Word became flesh - John 1:14], the butter is representing the "Grace of Father", and the milk is representing the "Spirit of Truth", that's what the Bible is Says The Word came to this world with full of Grace and Truth [Full of Grace and Truth - John 1:14].
If we have a closer look, the Butter, Milk & Calf, all three of them came from the Cow, but to serve, Abraham had to kill the Calf, and served with butter and milk that the Cow produced for the Calf.
Can any Cow produce the butter and milk for Human? No, it cannot, First the Cow has to give Birth, then the Cow's body would produce the butter and milk for her own Calf, So when the Calf invites us to receive Milk, obviously the Calf would say come and have my Mom's Milk - For it is not you who speak, but the Spirit of your Father speaking through you - Matthew 10:20
And at the time, when the Cow invites us, the Cow would say come and have the Milk of my Calf - And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!” - Galatians 4:6
At the end, All that Cow has produced is for her own Calf, and we are not worthy of any of it, and we just receiving it as Gift, and the Cow still has to produce one final thing that is the power of resurrection, for that the Calf has to be Slaughtered, because no one in this world is worthy enough for heaven to produce the "Power of Resurrection", and that was the reason our Savior Jesus Christ went to the Cross and given himself so that we can also riase from the dead - 13.When the Spirit of truth comes, he will guide you into all the truth, for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come. 14.He will glorify me, for he will take what is mine and declare it to you. 15.All that the Father has is mine; therefore I said that he will take what is mine and declare it to you - John 16:13-15
Father's Gift or Son's Gift
That was the Reason, When Apostle Paul spoke about God's Grace, He was calling it out as "Grace of Father" and also "Grace of Son" - But the free gift is not like the trespass. For if many died through one man's trespass, much more have the grace of God and the free gift by the grace of that one man Jesus Christ abounded for many - Romans 5:15
And in the same way, When he spoke Holy Spirit, He is mentioning as "Spirit of Father" and also "Spirit of Son" - 8.Those who are in the flesh cannot please God. 9.You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him. 10.But if Christ is in you, although the body is dead because of sin, the Spirit is life because of righteousness - Romans 8:8-10
Abraham's Serving Order
And there is a good reason for Abraham's serving order, first he served the butter, then milk, and then calf, because the Butter which represents the Grace of God that draws us to his Son Jesus Christ - 44.No one can come to Me unless the Father who sent Me draws him; and I will raise him up at the last day. 45.It is written in the prophets, And they shall all be taught by God. Therefore everyone who has heard and learned from the Father comes to Me - John 6:44-45 And Bible calls Father grace as "Spirit of Grace" - How much worse punishment, do you think, will be deserved by the one who has trampled underfoot the Son of God, and has profaned the blood of the covenant by which he was sanctified, and has outraged the Spirit of grace? Hebrews 10:29
And then Abraham served the Milk which represents the Holy Sprit, who prepares and gives understanding and boldness to confess Jesus Christ is God - Therefore I want you to understand that no one speaking in the Spirit of God ever says “Jesus is accursed!” and no one can say “Jesus is Lord” except in the Holy Spirit - 1 Corinthians 12:3 And Bible calls Holy Sprit as "Spirit of Truth" - even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him. You know him, for he dwells with you and will be in you - John 14:17