Is shaving forbidden
in the Holy Scriptures?

The shaving of the head and beard (in part and sometimes in totality), and making marks and cuttings in their flesh were pagan customs and practices used in MOURNING FOR THEIR DEAD. Those pagan customs and practices used in mourning for their dead are mentioned by Isaiah and Jeremiah concerning the prophesied death and destruction by YAHWEH pronounced upon the land of Moab for their sins.

Isaiah 15 (2) He is gone up to Bajith, and to Dibon, the high places, to weep [for their dead]: Moab shall howl over Nebo, and over Medeba: on all their heads shall be baldness, and every beard cut off. (3) In their streets they shall gird themselves with sackcloth: on the tops of their houses, and in their streets, every one shall howl, weeping abundantly.

Jeremiah 48 (37) For every head shall be bald, and every beard clipped: upon all the hands shall be cuttings, and upon the loins sackcloth. (38) There shall be lamentation [for their dead] generally upon all the housetops of Moab, and in the streets thereof: for I have broken Moab like a vessel wherein is no pleasure, saith YAHWEH.

Let us put the following verses in the context in which I am convinced that they were meant. The context was a warning against being ceremonially defiled for the dead by touching the dead and a warning against being ceremonially defiled for the dead by using those pagan customs and practices of mourning for their dead. (Also remember that anyone would become ceremonially defiled by touching the dead body of a dead person or by touching someone else who was unclean from touching a dead body of a dead person.)

Leviticus 21 (1) And YAHWEH said unto Moses, Speak unto the priests the sons of Aaron, and say unto them, There shall none be defiled FOR THE DEAD among his people: (2) But for his kin, that is near unto him, that is, for his mother, and for his father, and for his son, and for his daughter, and for his brother, (3) And for his sister a virgin, that is nigh unto him, which hath had no husband; for her may he be defiled [i.e. by touching their dead body]. (4) But he shall not defile himself, being a chief man among his people, to profane himself. (5) They shall not make baldness upon their head, neither shall they shave off the corner of their beard, nor make any cuttings in their flesh [for their dead].

Leviticus 19 (1) And YAHWEH spake unto Moses, saying, (2) Speak unto all the congregation of the Children of Israel, and say unto them, Ye shall be holy: for I, YAHWEH your Elohim am holy. (27) Ye shall not round the corners of your heads, neither shalt thou mar the corners of thy beard. (28) Ye shall not make any cuttings in your flesh FOR THE DEAD, nor print any marks upon you: I am YAHWEH.

Deuteronomy 14 (1) Ye [the Children of Israel] are the children of YAHWEH your ELOHIM: ye shall not cut yourselves, nor make any baldness between your eyes FOR THE DEAD. (2) For thou art a holy people unto YAHWEH thy Elohim, and YAHWEH hath chosen thee to be a peculiar people unto HIMSELF, above all the nations that are upon the earth.

My conclusion: Even though YAHWEH put hair on our face to help protect it from the elements of nature, I find no scripture prohibiting us from shaving other than for the purpose of MOURNING FOR THE DEAD.