>>164839791/x
I note that it was difficult to find material on this from Google, and had to use Yandex to find some links.
From Wikipedia:
>Tefillin or phylacteries, are a set of small black leather boxes with leather straps containing scrolls of parchment inscribed with verses from the Torah. Tefillin are worn by adult Jews during weekday morning prayers...>The arm-tefillah (or shel yad [literally "of the hand"]) is placed on the upper (non-dominant) arm, and the strap wrapped around the forelimb, hand and middle finger; while the head-tefillah (or shel rosh [literally "of the head"]) is placed between the eyes at the boundary of the forehead and hair. They are intended to fulfill the Torah's instructions to maintain a continuous "sign" and "remembrance" of the Exodus from Egypt, as they were originally worn all day, from sunrise to sunset.>The biblical verses often cited as referring to tefillin are obscure. Deuteronomy 11:18, for instance, does not designate explicitly what specifically to "bind upon your arm", and the definition of "totafot between your eyes" is not obvious. These details are delineated in the Oral Torah. At least as early as the 1st century CE, many Jews understood the verses literally and wore physical tefillin, as shown by archaeological finds at Qumran and a reference in the New Testament. And there are images of it being worn widely available; it includes the wearing of a Black Cube on one's forehead.
https://katz.sas.upenn.edu/resources/blog/saturn-and-jews