Adam Clarke on John 4:21

The hour cometh, etc. - The time was now at hand in which the spiritual worship of God was about to be established in the earth, and all the Jewish rites and ceremonies entirely abolished.

Worship the Father - This epithet shows the mild, benignant, and tender nature of the Gospel dispensation. Men are called to worship their heavenly Father, and to consider themselves as his children. In reference to this, our Lord's prayer begins, Our Father, who art in heaven, etc. See Joh 4:23.