****obey your parents in the Lord****
Is that a phrase ever found in Scripture before? Why does Paul phrase it this way, rather than just, obey your parents?
*****And with adults and so what does that have to do with infant/adult baptism?*****
Nothing if one obstinately refuses to see the connection between the fact that children were brought to Jesus and Scripture is not specific about what were their ages.
And we see that Jesus laid His hands upon them and said “Let them come to me. Do not hinder them.”
Children were a part of Jesus’ ministry, their parents brought them to Him and when the parents “household” heard and believed, the parents would have spoken for and acted for their children, because that is what parents do.
The age of the children here is irrelevant, Jesus was laying his hands upon them not baptizing them.
“Is that a phrase ever found in Scripture before? Why does Paul phrase it this way, rather than just, obey your parents?”
Obeying their parents was obedience to the Lord. Nothing is suggestive of baptism.
There simply is no support in Scripture for infant baptism or that of a child too young to be instructed as a disciple.
Disciple, baptism, teaching them all things Jesus commanded is the pattern.