The second element is formal observance. There must be an outward, visible sign, or form, in an ordinance. Prayer is an ordinance of divine worship. But it is not a rite, or ceremony. Men are commanded to pray always.
Charity is an ordinance, but it is devoid of ceremony.
We ceremonially observe baptism, the Communion, the washing of feet. This is what Christ did. There must be matter, so that there may be form and ceremony. In baptism the sensuous element is water. In the Communion the elements are bread and wine.