¹⁷ Iron sharpens iron; so a man sharpens the countenance of his friend [to show rage or worthy purpose].

¹⁶ For because of Him the whole body (the church, in all its various parts), closely joined and firmly knit together by the joints and ligaments with which it is supplied, when each part [with power adapted to its need] is working properly [in all its functions], grows to full maturity, building itself up in love.