It appears to be of the priniciples but its rare to even catch those preached without confusion.
Heb 6:1-2 Therefore leaving the principles of the doctrine of Christ, let us go on unto perfection;
not laying again the foundation of repentance from dead works,
and of faith toward God,
Of the doctrine of baptisms,
and of laying on of hands,
and of resurrection of the dead,
and of eternal judgment.
Hebrews 6:3 And this will we do, if God permit.
Even back then Simon Magus could see for himself the Holy Ghost was given this way
Acts 8:18 And when Simon saw that through laying on of the apostles' hands the Holy Ghost was given, he offered them money, (he was perverse though)
Acts 8:19 Saying, Give me also this power, that on whomsoever I lay hands, he may receive the Holy Ghost.
Just before this
Acts 8:14 Now when the apostles which were at Jerusalem heard that Samaria had received the word of God, they sent unto them Peter and John:
Acts 8:15 Who, when they were come down, prayed for them, that they might receive the Holy Ghost:
Acts 8:16 (For as yet he was fallen upon none of them: only they were baptized in the name of the Lord Jesus.)
Acts 8:17 Then laid they their hands on them, and they received the Holy Ghost.
We see this with Saul/Paul with Ananias (who the Lord sent)
Acts 9:10 And there was a certain disciple at Damascus, named Ananias; and to him said the Lord in a vision, Ananias. And he said, Behold, I am here, Lord.
Acts 9:11 And the Lord said unto him, Arise, and go into the street which is called Straight, and enquire in the house of Judas for one called Saul, of Tarsus: for, behold, he prayeth,
Acts 9:12 And hath seen in a vision a man named Ananias coming in, and putting his hand on him, that he might receive his sight.
Acts 9:17 And Ananias went his way, and entered into the house; and putting his hands on him said, Brother Saul, the Lord, even Jesus, that appeared unto thee in the way as thou camest, hath sent me, that thou mightest receive thy sight, and be filled with the Holy Ghost.
Acts 9:18 And immediately there fell from his eyes as it had been scales: and he received sight forthwith, and arose, and was baptized.
And here as well
Acts 19:1 And it came to pass, that, while Apollos was at Corinth, Paul having passed through the upper coasts came to Ephesus: and finding certain disciples,
Acts 19:2 He said unto them, Have ye received the Holy Ghost since ye believed? And they said unto him, We have not so much as heard whether there be any Holy Ghost.
Acts 19:3 And he said unto them, Unto what then were ye baptized? And they said, Unto John's baptism.
Acts 19:4 Then said Paul, John verily baptized with the baptism of repentance, saying unto the people, that they should believe on him which should come after him, that is, on Christ Jesus.
Acts 19:5 When they heard this, they were baptized in the name of the Lord Jesus.
Acts 19:6 And when Paul had laid his hands upon them, the Holy Ghost came on them; and they spake with tongues, and prophesied.
And here as well....
1 Ti 4:14 Neglect not the gift that is in thee, which was given thee by prophecy, with the laying on of the hands of the presbytery.
1 Ti 4:15 Meditate upon these things; give thyself wholly to them; that thy profiting may appear to all.
1 Ti 4:16 Take heed unto thyself, and unto the doctrine; continue in them: for in doing this thou shalt both save thyself, and them that hear thee.
Just a few examples that can be found