3 John 2
"Beloved, I wish above all things that thou mayest prosper and be in health, even as thy soul prospereth." KJV
"The physical constitution of Jesus, as well as His spiritual development, is brought before us in these words,"the child grew," and "increased in stature." In childhood and youth attention should be given to physical development. Parents should so train their children in good habits of eating and drinking, dressing, and exercise, that a good foundation will be laid for sound health in afterlife. The physical organism should have special care, that the powers of the body may not be dwarfed, but developed to their full extent. This places the children and youth in a favorable position, so that, with proper religious training, they may, like Christ, wax strong in spirit."
Child Guidance, p. 187.1