Straight and Narrow, Not Straightened Arrow

Which is correct to describe “a morally upright path” — straight and narrow or straightened arrow? The latter is picturesque, but the vastly more common term is straight and narrow. The original expression was strait and narrow, a reference to a verse in early translations of the Sermon on the Mount rendered as Enter ye in at the strait gate. Here, the word strait is a synonym for “narrow” and refers to the path of righteousness, which allows for little deviation. The same strait meaning “narrow” is also a part of the tight, confining garment known as a straitjacket, as well as strait meaning “a narrow passage,” and dire straits, initially “difficult or narrow passages of water” and later more generally “an extremely challenging situation.” This is part of a complete episode.