Q. 10. What are the personal properties of the three persons in the Godhead?
A. It is proper to the Father to beget the Son, and to the Son to be begotten of the Father, and to the Holy Ghost to proceed from the Father and the Son from all eternity.
The next logical discussion since the one God is of three persons defines the essence, nature and relationships of these.
Vos’ commentary is good so I’ve copied all of it below. I like the way he answers question 1.
1. What is the meaning of the word begets in speaking of the Trinity? This word is the nearest there is in human language to set forth the relation between God the Father and God the Son.
2. How can it be shown from Hebrews 1:5-8 that the Son is not a created being, but was eternally begotten by the Father? The words “this day” in verse 5 do not imply that before that time the Son did not exist; rather “this day” is the day of eternity, as shown by verse 8, which calls the Son “God” and states that his throne is “for ever and ever.” If the Son had ever had a beginning, he would not be called “God.
3. In speaking of the three persons in the Godhead, why do we always name the Father first, the Son second, and the Holy Spirit third? Because the Bible speaks of the Father sending and operating through the Son and the Spirit; also the Bible speaks of the Son as sending and working through the Spirit. In the Bible this order is never reversed; the Bible never speaks of the Son working through the Father, or of the Holy Spirit sending or working through the Son.
4. What should be our attitude toward the truths of the Trinity? We should accept them with a reverent attitude, realizing that they are divine mysteries far beyond our power to explain or comprehend.