The cubit was the unit of length used in the Ancient Near East.
The cubit is an ancient unit of length based on the distance from the elbow to the tip of the middle finger. It was primarily associated with the Sumerians, Egyptians, and Israelites. The term cubit is found in the Bible regarding Noah’s Ark, the Ark of the Covenant, the Tabernacle, and Solomon’s Temple. The common cubit was divided into 6 palms × 4 fingers = 24 digits.[1] Royal cubits added a palm for 7 palms × 4 fingers = 28 digits.[2] These lengths typically ranged from 44.4 to 52.92 cm (1 ft 5+1⁄2 in to 1 ft 8+13⁄16 in), with an ancient Roman cubit being as long as 120 cm (3 ft 11 in).Cubits of various lengths were employed in many parts of the world in antiquity, during the Middle Ages and as recently as early modern times. The term is still used in hedgelaying, the length of the forearm being frequently used to determine the interval between stakes placed within the hedge.
https://en.wikipedia.org/wiki/Cubit
There is no absolute fixed length that was used universally for the cubit, but there were standards for a specific region.
The standard of the cubit (Hebrew: אמה) in different countries and in different ages has varied. This realization led the rabbis of the 2nd century CE to clarify the length of their cubit, saying that the measure of the cubit of which they have spoken “applies to the cubit of middle-size”.[12] In this case, the requirement is to make use of a standard 6 handbreadths to each cubit,[13][14] and which handbreadth was not to be confused with an outstretched palm, but rather one that was clenched and which handbreadth has the standard width of 4 fingerbreadths (each fingerbreadth being equivalent to the width of a thumb, about 2.25 cm).[15][16] This puts the handbreadth at roughly 9 cm (3+1⁄2 in), and 6 handbreadths (1 cubit) at 54 cm (21+1⁄2 in). Epiphanius of Salamis, in his treatise On Weights and Measures, describes how it was customary, in his day, to take the measurement of the biblical cubit: “The cubit is a measure, but it is taken from the measure of the forearm. For the part from the elbow to the wrist and the palm of the hand is called the cubit, the middle finger of the cubit measure being also extended at the same time and there being added below (it) the span, that is, of the hand, taken all together.”[
https://en.wikipedia.org/wiki/Cubit
The dimensions of the TS is not fixed either since it’s a cloth. But it’s roughly 14’3″ (171″) by 3’7″ (43″). The dimensions is extremely close to a 4:1 ratio.
Measuring 4.3 metres (14 feet 3 inches) long and 1.1 metres (3 feet 7 inches) wide
https://www.britannica.com/topic/Shroud-of-Turin
The measurements correlate with the Assyrian cubit.
Now during the 19th century the great archaeological pioneer Sir Flinders Petrie, along
with a co-researcher, Oppert, took numerous measurements of ancient buildings in Babylon
from which they found the metrological value of the Assyrian cubit to be almost 21.5 inches.
Other archaeologists have since calculated just over 21.6 inches. So the Assyrian cubit has
been recorded as 21.6 plus or minus 0.2 inches – and this is just what the Shroud conforms to.Taking the lower limit of 21.4 inches, the results are:
21.4 inches x 8 = 171.2 inches
21.4 inches x 2 = 42.8 inchesShroud recorded length = 171.0 inches
Shroud recorded width = 43.0 inches
https://www.shroud.com/pdfs/n24part6.pdf
So, the shroud has the dimensions of 8 x 2 cubits, which correlates with an ancient origin.
Another analysis of the shroud dimensions:
https://debatingchristianity.com/forum/viewtopic.php?p=1119548#p1119548