The first point, here, is the manner in which the phenomena of the occasion were introduced. “Suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting.” That this was designed to be a significant sign, would seem certain in the presence of all the other significant features of the occasion. And its meaning is not obscure. From the Greek verb, _pneo_, to blow, are derived two nouns, _pneuma_ and _pnoē_. These words are nearly identical in meaning, except that _pneuma_ is by the sacred writers appropriated to designate the Holy Spirit. It, and the Hebrew _ruagh_, which is appropriated in a like manner, both mean, primarily, the air, the wind; and hence, the breath, the soul of man, a spirit, the Spirit of God. In all these significations, they are found, the one in the Hebrew Scriptures of the Old Testament, and the other in the Greek of the Septuagint version. We have seen how largely the figure of water is used as a symbol of the Spirit. Its chief propriety as thus employed appears in its effects upon the earth and the creatures, penetrating and fertilizing the soil, washing away defilement, and refreshing the thirsty; while as rain from heaven, it traces the descent of the Spirit from the throne of God. In wind, or air in motion, or the breath, we have another symbol, familiar in the Scriptures, and equally interesting and significant. Its peculiar fitness consists in its relation to its source, as representing the Third Person as the _Spiritus_ or breath, “which proceedeth from the Father;” and in its nature, as essential to sustain life in the animate creation. Says the Psalmist, “By the Word of the Lord were the heavens made, and all the host of them by the breath (_tō pneumati_, by the Spirit) of his mouth.”—Ps. xxxiii, 6. The word, _pnoē_, is that which designates the “rushing, mighty _wind_” of Pentecost. It is used in the Septuagint in the sense of wind, stormy or violent wind, the breath, the soul, the spirit. Its relation to _pneuma_ may be seen in such places as follow.—“He that giveth _breath_ (_pnoē_) to the people upon it and _spirit_ (_pneuma_) to them that walk therein.”—Isa. xlii, 5. “The _spirit_ (_pneuma_) should fail before me, and the souls (_pnoēn_) which I have made.”—Ibid. lvii, 16. “At the _blast_ (_pnoēs_) of the _breath_ (_pneumatos_) of His nostrils.”—2 Sam. xxii, 16. “All the time my _breath_ (_pnoēs_) is in me, and the _Spirit_ (_pneuma_) of God is in my nostrils.”—Job xxvii, 3. “The _Spirit_ (_pneuma_) of God hath made me, and the _breath_ (_pnoē_) of the Almighty hath given me life.”—Job. xxxiii, 4. In the New Testament, we have the words of Jesus to Nicodemus,—“The _wind bloweth_ (_pneuma pnei, the Spirit breatheth_), where it listeth.”—John iii, 8. And in this same book of the Acts, is the testimony of Paul to the Athenians that—“He giveth to all, life and _breath_ (_pnoēn_), and all things.”—Acts xvii, 25.