If you would ask any semicha student which of the מלאכות ( forbidden categories of shabbos work) are the most complex, my bet would be that it would be a tough choice between בשול ( cooking ) and הוצאה (transferring.)

If that student  had extended his usual semicha studies to include  ערובין , it would become a no brainer- הוצאה would definitely scoop the prize .

This is the only one of the מלאכות that takes up virtually an entire masechta ( Eruvin) , as well as at least 4 full chapters of Shabbos.

It is also one of the only 2 מלאכות ( I stand to be corrected ) that gets it own source:

• the מלאכה of הבערה ( lighting a fire) is specifically mentioned  (Shmos  35/3) – לא תבערו אש בכל מושבותיכם ביום השבת  ( You may not kindle a fire in any of your dwelling places on the Sabbath day .)
  Chazal debate why it is singled out and their are 2 major approaches to this (הבערה ללאו יצאת או הבערה לחלק יצאת)  , but thats  not for this post.
• Our Gemara asks where the source is that הוצאה is forbidden on shabbos, and brings a passuk ויעבירו קול במחנה  (Shmos 36/6) , an instruction to stop bringing ( transferring) things for the Mishkan. 

Given that we are already aware from various sugyos that we have studied that the source for all the מלאכות is the verse “You shall not do any מלאכה ” and the  proximity of the verse that discusses Shabbos to the one that discusses the משכן (sanctuary) , teaches us that the מלאכות referred to in the prohibition are those that were done in the work of the משכן.

In our very Mishna, this same idea is applied to the מלאכה of הוצאה to explain why passing something from one private domain to another through a public domain is forbidden yet throwing is not, according to Chachamim ( Rabbi Akiva of course disagrees and forbids throwing as well- welcome to הזורק! )

In chapter 4 of our  Masechta (Shabbos 49b) , it also specifically mentioned that both הוצאה   ( literally taking out ) and  its תולדה ( derivative )  הכנסה ( bringing in ) , are derived from what was done in the Mishkan.

As such, the question screaming out at us is why do we need a separate passuk to teach us the prohibition of הוצאה and its תולדות of הכנסה, זריקה, etc , when it was  already one of the 39 מלאכות done in the Mishkan and is indeed derived from there too!

Tosfos on the first daf of the Masechta ( Shabbos 2a ” פשט” ) , deals with this  question at length, and focuses on the idea that הוצאה is a מלאכה גרועה ( inferior מלאכה ).

This seems to be because unlike most מלאכות where an actual physical change ( usually an improvement) is made in the object the מלאכה is applied to,  transferring an item from one domain to another does not have any physical affect at all- it remains the same item as it was before.

Tosfos points out that it is so questionable whether this should even qualify as a מלאכה  that transferring from one adjoining  private domain to another is completely permitted on a biblical level while transferring from a private domain to a public domain is forbidden, despite their similarity in terms of the action done!

The question that still bothers Tosfos though, is the converse .

If we already know that הוצאה is forbidden from a separate  verse despite it being a מלאכה גרועה , then why does our Mishna and other sugyos have to show that it was done in the Mishkan ?

He answers with the radical idea that had we not been able to show that הוצאה was indeed one of the מלאכות in the Mishkan, we would have learnt from the passuk that explicitly forbids it that ANY melacha like action, (perhaps even a weak one like הוצאה) , is forbidden on shabbos, even if it was NOT done in the Mishkan !

We thus need a separate passuk to teach us that even though it is a מלאכה גרועה, it is still included in the prohibition with its sister melachot that were done in the Mishkan, but we need the fact that it was in fact done in the Mishkan to save the famous rule that only מלאכות done in the Mishkan are in fact forbidden !

It thus comes as a leniency rather than a stringency  as we thought .

But what would we have done with the דרשה that derives the forbidden מלאכות from the משכן due to proximity of verses ?

Tosfos suggests that this would have simply been used  to teach us something else , perhaps a fascinating statement about how he views the world of דרשות in general , but thats for another time perhaps …

Lets take a minute go consider how far-reaching this suggestion is- The golden rule that we always take for granted about the connection between the Mishkan and Shabbos would have come tumbling down in a moment had Chazal not shown that this “inferior Melacha” was also done on the Mishkan!

There is another, philosophical lesson, I would like to learn from this .

What seems to us like the weakest of Melacho, one that has NO physical impact on the item at all, to the point that it needs its own unique prohibition, has become the Melacha which our Masechta opened up with, that occupies 2 of the longest and most complex chapters of the Masechta, and also gets its own entire Masechta virtually to itself !

Despite the emphasis placed on the laws of לשון הרע ( gossip) and אונאת דברים (offending people ), in practise , we  still often tend to harbour  the mistaken belief that ” sticks and stones can break my bones but words can never harm me .”
So long as one doesn’t actually physically hurt a person, it is OK to hurt him emotionally, after all emotions cannot be seen or measured !

Yet the message of this מלאכה is precisely the opposite. 

If a constructive action that involves no physical improvement to an item can not only be considered מלאכת מחשבת , a significant form of work, but even dominate all the other מלאכות in the time spent studying it , how much more so should we focus on the significance of non physical damage that appears to be less significant, but in fact, can be as damaging , or even more so, than physical actions, , as we know from the innocent  lives that have been utterly ruined by lashon harah.