A prayer asking for God's covenant faithfulness on the children we baptize, this song is adapted from a baptism text written by Thomas Haweis (b. Redruth, Cornwall, England, 1734; d. Bath, England, 1820) and published in the enlarged edition of his Carmina Christo (1808). The Psalter Hymnal Revision Committee made some significant changes in the text to express more modern Reformed theological ideas about baptism.
Bert Polman, Psalter Hymnal Handbook
The inclusion of children at baptism is taught in Heidelberg Catechism, Lord’s Day 27, Question and Answer 74 when it says, “Children as well as adults are included in God’s covenant and people” and Belgic Confession, Article 34 which says, “…our children ought to be baptized and sealed with the sign of the covenant…"