Thats right but Jesus had already died and resin from the dead when he breathed upon his disciples to "receive the Holy Spirit"
The baptism of the Holy Spirit which Jesus said to his followers would happen to them on the day of Pentecost was going to come from His Father as Jesus proclaimed.
Luke 24:49 "I am going to send you what my Father has promised. But for now, stay in the city. Stay there until you have received power from heaven."
Then we have this scripture which I find very interesting......
John 5:21 For as the Father raises the dead and gives life to them, even so the Son gives life to whom He will.
The Father gives life to whoever he desires and the Son also gives life to ever he desires.
Jesus breathing upon his disciples was giving eternal life to them, but they still needed the power to complete their mission and that is what the Father gave on the day of Pentecost.
I agree the Holy Spirit gave them the power they needed to accomplish their mission.
But let's get to the purpose of the tongues on the day of Pentecost in Acts 2.
Pentecost was a feast that took place 50 days after the Passover. Jews from all over the Roman Empire came to Jerusalem to celebrate this feast. They came from countries that spoke different languages, but they all had one thing in common, they were all Jews.
I think we can agree that tongues are a sign to the unbelieving, as Paul said.
1 Cor. 14:22
"Wherefore tongues are for a sign, not to them that believe, but to them that believe not: but prophesying serveth not for them that believe not, but for them which believe."
The tongues on the day of Pentecost was for the Jews who came from all over the world to Jerusalem on Pentecost. It was a sign for them to know that what was taking place was real. Some 3,000 Jews were saved that day at Pentecost and the sign of the tongues is what made it possible.
When the Holy Spirit fell on these disciples and they began to speak in tongues for a sign to the unbelieving Jews, what was really taking place was the grand entrance of the Holy Spirit to indwell man permanently. This was the fulfillment of the promise of Christ.
John 14:16-17
"And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever;
Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you."
This is what happened at Pentecost, the Holy Spirit came to dwell in man, to make his home in the soul and spirit of man. This was not possible for the Old Testament saints. Christ had not yet paid the sin debt.
The tongues were only a sign to the Jews who spoke different languages. Pentecost is not about a baptism of tongues, It's about the Holy Spirit coming and immersing/baptizing man in a new dimension to be with him forever.