18. (Joh 1:13). The believer's regeneration is the highest example of nothing but good proceeding from God.
      Of his own will--Of his own good pleasure (which shows that it is God's essential nature to do good, not evil), not induced by any external cause.
      begat he us--spiritually: a once-for-all accomplished act (1Pe 1:3, 23). In contrast to "lust when it hath conceived, bringeth forth sin, and sin . . . death" (Jas 1:15). Life follows naturally in connection with light (Jas 1:17).
      word of truth--the Gospel. The objective mean, as faith is the appropriating mean of regeneration by the Holy Spirit as the efficient agent.
      a kind of first-fruits--Christ is, in respect to the resurrection, "the first-fruits" (1Co 15:20, 23): believers, in respect to regeneration, are, as it were, first-fruits (image from the consecration of the first-born of man, cattle, and fruits to God; familiar to the Jews addressed), that is, they are the first of God's regenerated creatures, and the pledge of the ultimate regeneration of the creation, Ro 8:19, 23, where also the Spirit, the divine agent of the believer's regeneration, is termed "the first-fruits," that is, the earnest that the regeneration now begun in the soul, shall at last extend to the body too, and to the lower parts of creation. Of all God's visible creatures, believers are the noblest part, and like the legal "first-fruits," sanctify the rest; for this reason they are much tried now.

JFB.