The Lord explained His descent from heaven and His ascension into it to Nicodemus when He said "No one has ascended to heaven but He who came down from heaven, that is, the Son of Man who is in heaven" (Jn. 3:13). What is meant here by heaven is the heaven of heavens which nobody has ascended to or descended from except Christ, being the Second Person of the Holy Trinity, "who is in the bosom of the Father" (Jn. 1: 18). The heaven of heavens is where the throne of God is, because in the Sermon on the Mount the Lord said that heaven is God's throne (Matt. 5:34). The expression 'the Son of Man who is in heaven' means that Christ was in heaven while He was on earth. Being on earth and in heaven at the same time is proof of His Divinity. The event of His ascension into heaven (Acts. 1:9) is the fulfillment of the words He said to His disciples: "Again, I leave the world and go to the Father" (Jn. 16:28).