"I will take of the spirit that is upon thee, and will put it upon them..."

The Holy Prophet Moses receiving the Law on Mount Sinai, which became the inspiration for the first feast of Pentecost in the Old Testament (source)

  
And the Lord said to Moses, Gather me seventy men from the elders of Israel, whom thou thyself knowest that they are the elders of the people, and their scribes; and thou shalt bring them to the tabernacle of witness, and they shall stand there with thee.  And I will go down, and speak there with thee; and I will take of the spirit that is upon thee, and will put it upon them; and they shall bear together with thee the burden of the people, and thou shalt not bear them alone...And Moses went out, and spoke the words of the Lord to the people; and he gathered seventy men of the elders of the people, and he set them round about the tabernacle.  And the Lord came down in a cloud, and spoke to him, and took of the spirit that was upon him, and put it upon the seventy men that were elders; and when the spirit rested upon them, they prophesied and ceased. And there were two men left in the camp, the name of the one was Eldad, and the name of the other Modad; and the spirit rested upon them, and these were of the number of them that were enrolled, but they did not come to the tabernacle; and they prophesied in the camp.  And a young man ran and told Moses, and spoke, saying, Eldad and Modad prophesy in the camp.  And Joshua the son of Naue, who attended on Moses, the chosen one, said, My lord Moses, forbid them.  And Moses said to him, Art thou jealous on my account? and would that all the Lord's people were prophets; whenever the Lord shall put his spirit upon them.

-Numbers 11:16-17, 24-49, Read at the Great Vespers for the Feast of Pentecost

(source)

  

The Holy Spirit and the Preparation of the Throne of the Lord (source)

  

Through the prayers of our Holy Fathers, Lord Jesus Christ our God, have mercy on us and save us! Amen!