For I will pour water on the thirsty land, and streams on the dry ground; I will pour out my Spirit on your offspring, and my blessing on your descendants. - Isaiah 44:3

God promised his people that he would pour out his Spirit. With the prophet Joel, God said, “I will pour out my Spirit on all people.” In Acts 2, when Israel was gathered for the Feast of Weeks (Pentecost) the Holy Spirit fell upon the followers of Jesus and the crowds heard them speak in each of their own languages. The disciples and Peter were telling the people of the wonders of God and the salvation that comes through Jesus Christ.