Crossing the threshold

What we may know as a sentence to explain someone passing into a 'new phase' of their life, or perhaps crossing into something that was previously not possible, has a slightly unsure origin, and hopefully this post may bring some more ideas into what it actually means.

Firstly, a threshold is now known as a strip of wood at the bottom of a doorway which is crossed in order to get into or out of a room.

It can also be known as a barrier or point that needs to be crossed or exceeded in order to attain or reach something. Without passing that "threshold" the goal or objective would not be achieved. Kinda what the alien needed to cross to start its life in this world

Lets break down some of the history of the term:

• Thresh: the method of removing grain or plants from their holders or husks/chaff in order to get to the edible portion of the plants, and then separating the edible parts from the empty shells/chaff left behind. For example wheat or beans. This can take place in numerous ways, whether by beating the husks in bags, with flails, on hard floors and walking on them to even having machines today that do it all in a single pass (combine harvester).
  Makes the parables more interesting when speaking of chaff being "Are they as straw before the wind, And like chaff which the storm carries away?".
  

• Theory 1: It is believed that historically, due to the homes having dirt floors, and the occupants would enter in and out regularly even in wet weather, the place would become a mess and even muddy and difficult to live in.
  they would therefore make use of the leftover husks from the threshing that had taken place, and spread it over the floor in order to manage the mess that was there previously. essentially making a carpet of sorts that they can then walk on. But due to the slippery nature of empty husks, it would be needed to have a plank, or wood "threshold" in order to keep the thresh in place INSIDE the home, and not scattered all over the front of the home.

• Theory 2: Is that the act of crossing over the beam on the floor, you are in essence 'beating' the beam, and by so doing doing the same as in the act of threshing. Beating the husks till the grain or beans are separated from the husks/chaff. thus being called a threshold.
  Actually an interesting fact is that to thrash someone may have been derived from thresh, since you are beating that person (thrashing them) similarly to the actions on your crop.
  

Now neither of these meanings could be the actual truth, as there is little proof that this is the case, but I could find no other viable meanings, and they make sense to me.
I do find it interesting that we use these sorts of terms every day, and often have no clue as to the origin or meaning of the terms.

Perhaps one day we will cross that threshold :)

[Images credit Parish of our lady of perpetual help, Crossroads Congregation of Messiah, Entertainment weekly, Thesaurus plus]