WSC Q.52: What are the reasons annexed to the second commandment?
The reasons annexed to the second commandment are, God’s sovereignty over us, (Ps. 95:2–3) his propriety in us, (Ps. 45:11) and the zeal he hath to his own worship. (Exod. 34:13–14)
WLC Q.110: What are the reasons annexed to the second commandment, the more to enforce it?
The reasons annexed to the second commandment, the more to enforce it, contained in these words, For I the Lord thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me; and showing mercy unto thousands of them that love me, and keep my commandments; (Exod. 20:5–6) are, besides God’s sovereignty over us, and propriety in us, (Ps. 45:11. Rev. 15:3–4) his fervent zeal for his own worship, (Exod. 34:13–14) and his revengeful indignation against all false worship, as being a spiritual whoredom; (1 Cor. 10:20–22, Deut. 32:16–20) accounting the breakers of this commandment such as hate him, and threatening to punish them unto divers generations; (Hosea 2:2–4) and esteeming the observers of it such as love him and keep his commandments, and promising mercy to them unto many generations. (Deut. 5:29)