He starts off the page (here is the link to the page so you can see it; this is my understanding of it) by explaining thatולזבולן אמר שמח זבולן בצאתך means that through Zevulon's הוצאות (hinted by בצאתך) for Torah (his giving money to Yissachar so he can learn Torah) the Torah is his reward, but Zevulon will also be happy (שמח) in this world immediately since he needs to make more money in order to support talmidei chachomim. (See link for the rest) This seems to be the lesson we should take out of it. By supporting people who learn Torah – everyone according to their means – we can be worthy of getting parnasa. This should get those people that speak disparagingly of talmidei chachomim that are supported to stop doing so, as really the talmidei chachmim are doing the giver a favor.
If I may add: שמח זבולן is equal to באמת, hinting at dealing honestly. שמח זבולן is also meramez to simcha being mesugal for parnasa. Reb Nosson Breslover once told someone with financial troubles that simcha is mesugal for paranasa. The man replied that it was difficult to be happy in his present situation. Reb Nosson responded: "But, what won't a person do for parnasa?" (The same story is told over with the Yismach Yisroel of Alexander) Reb Mendel Riminover says a remez to simcha being mesugal for parnaas is the last letters of פותח את ידך and והיית אך שמח are the same and they are a Name connected to parnasa. If I may add, the first letters of שמח זבולן are equal to the first letters of והיית אך שמח. This is also meramez in the Mishna: איזה הוא עשיר השמח בחלקו. How does one become an עשיר? השמח בחלקו – by being happy with one's lot.
זבולן equals המן reminding us of פרשת המן. Leah said regarding זבולן that Hashem gave her a זבד טוב. Rashi says that this means as Onkelos translates it, חלק טב – "a good portion." The gematria of חלק is equal to הצלחה. The word זבולן in א״ת ב״ש is עשפכט, equal to 479 – the gematria of בזעת, as in בזעת אפיך תאכל לחם. The last letters of שמח זבולן בצאתך equal לחם. This posuk teaches us that although there are people that seem to amass great wealth without breaking a sweat, the posuk is teaching that if one thinks בזעת אפיך, meaning one's own efforts are what makes - as the posuk says: ואמרת בלבבך כחי ועצם ידי עשה לי את החיל הזה - then no matter how much one may have it's never enough (as Chazal teach that if one has 100 he wants 200). Then despite all you may have, תאכל לחם, it seems like you only have bread. The gematria of בזעת with the kolel is equal to the last letters of ואמרת בלבבך כחי ועצם ידי. The posuk then says: עד שובך אל האדמה כי ממנה לקחת כי עפר אתה ואל עפר תשוב - which can be read as: until he does teshuva and realizes that he is just dust and powerless, as Avrohom Avinu said: ואנכי עפר ואפר – "I am but dust and ashes". When someone comes to the realization that every single great idea and every single penny comes only from Hashem, (as is hidden in the pesukim, אפיך is equal to אלף, which alludes to Hashem who is One and the אלופו של עולם and the first letters of כחי ועצם equal 26, Hashem's Name) then even if he only has bread, he feels like he has everything, as the Mishna says: איזה הוא עשיר השמח בחלקו. He is then taken out of the curse of בזעת אפיך תאכל לחם. Hashem is saying אפיך, meaning "(by the sweat of) your face". When you take the ך off to make it אפי which would be referring to Hashem, then you have the first letters of פותח את ידך – we ask Hashem to "open His hand" since we can't do anything on our own. We can then realize there is only One that controls everything, as בזעת אפיך תאכל לחם is equal to שמע ישראל ד׳ אלקינו ד׳ אחד with the kolel.
Rashi on the words, בזעת אפיך, says: לאחר שתטריח בו הרבה – "after you toil a lot." But many toil and barely put food on the table? לאחר שתטריח - "After you toil" can mean two things: 1) After you are done with thinking that your own toil makes parnasa. 2) Reading it with a comma לאחר שתטריח, בו הרבה. After toiling hard by working on your emunah, thenבו הרבה . This doesn't mean quantity, rather quality. There will be lots of shefa; the money will come from the side of kedusha, as opposed to one who thinks he gets money on his own has the money coming from the "other side." A remez to this is that בו הרבה is the same gematria as טהור.
The Munkatcher Rov shows how the Name of זבולן is equal to 95 which will be equal to the Names of Hashem – י־ק־י־ק אדנ׳ - when Moshiach comes. After he speaks about the segula for parnasa, he says that we should understand that Nisan is a time of Geula. Exactly what he means I don't know, but as Rav Gamliel Rabinovitz shlita constantly says we need parnasa to live but we should remember that Hashem has no house, no wife (we are in golus), most of his children don't know how to say Shema. He says that Hashem doesn't even have bread, so to speak, as we say in korbonos: את קרבני לחמי. He says that besides constantly saying: "give me, give me", we should ask Hashem to rebuild His house.
We should all remember that the brocha of parnasa on this day comes from supporting talmidei chachomim. May we all be zoche to have parnasa berevach and do good things it, and may we be zoche to realize what we are missing without Hashem's House so we can daven properly for its rebuilding.