Pentecost Novena

The Pentecost Novena is the first of all novenas, nine days of prayer. After Jesus' Ascension into heaven, He commanded His disciples to come together in the upper room to devote themselves to constant prayer (Acts 1:14). They prayed for nine days before receiving the Holy Spirit on Pentecost.

You can find the novena at the following:

https://www.ewtn.com/devotionals/pentecost/seven.htm