Galatians 4:6

Abba - Aramaic/Hebrew for "father".

And because ye are sons - By faith in Christ Jesus, being redeemed both from the bondage and curse of the law; God - the Father, called generally the first person of the glorious Trinity, hath sent forth the Spirit - the Holy Ghost, the second person of that Trinity, of his Son - Jesus Christ, the third person of the Trinity - crying, Abba, Father! from the fullest and most satisfactory evidence that God, the Father, Son, and Spirit, had become their portion. For the explanation of the phrase, and why the Greek and Syriac terms are joined together here, see the notes on Mark 14:36, and on Romans 8:15 (note).

And because ye are sons - As a consequence of your being adopted into the family of God, and being regarded as his sons. It follows as a part of his purpose of adoption that his children shall have the spirit of the Lord Jesus.

The Spirit of his Son - The spirit of the Lord Jesus; the spirit which animated him, or which he evinced. The idea is, that as the Lord Jesus was enabled to approach God with the language of endearment and love, so they would be. He, being the true and exalted Son of God, had the spirit appropriate to such a relation; they being adopted, and made like him, have the same spirit. The "spirit" here referred to does not mean, as I:suppose: the Holy Spirit as such; nor the miraculous endowments of the Holy Spirit, but the spirit which made them like the Lord Jesus; the spirit by which they were enabled to approach God as his children, and use the reverent, and tender, and affectionate language of a child addressing a father. It is that language used by Christians when they have evidence of adoption; the expression of the warm, and elevated, and glowing emotions which they have when they can approach God as their God, and address him as their Father.

Crying - That is, the spirit thus cries, Πνεῦμα Pneuma - κράζον krazon). Compare the notes, Romans 8:26-27. In Romans 8:15 it is, "wherewith we cry."

Abba, Father - See the note at Romans 8:15. It is said in the Babylonian Gemara, a Jewish work, that it was not permitted slaves to use the title of Abba in addressing the master of the family to which they belonged. If so, then the language which Christians are here represented as using is the language of freemen, and denotes that they are not under the servitude of sin.

4:6 And because ye - Gentiles who believe, are also thus made his adult sons, God hath sent forth the Spirit of his Son into your hearts likewise, crying, Abba, Father - Enabling you to call upon God both with the confidence,and the tempers, of dutiful children. The Hebrew and Greek word are joined together, to express the joint cry of the Jews and gentiles.