There is a famous explanation of Vayikhu Ali Terumah/ Take for me a Terumah(type of donation). Why doesn't it say, Give me a donation? The lesson is that when you give something to God, you're really taking it for yourself, because we benefit when we give Sedaka. That is an important belief that we have to have. The Baal HaTurim in Shemot 30,12 points out that the word ונתנו VeNatnu can be read the same way backwards and forwards.
What's the lesson? That whatever you give to Sedaka comes back to you- you will not be missing anything. In the Ramban’s Sefer HaMitzvot, the 17th Mitzvah Lo Taaseh, is that we should not get upset when we give charity, and we shouldn't give it with an Ayin Ra’ah as if we just gave away money.
Rather, we should look at charity like I'm putting money into high-yield bonds. God will pay us back many times. That's what it means. Give Him, and it shouldn't bother you when you give it to Him, because God will bless you in all your deeds.
So we see that this concept that you're taking when you're giving is not just a mussar concept. According to the Ramban, this attitude, or the lack of such, is one of the 613 mitzvot in the Torah. There is no difference between shaving with a razor and giving charity and feeling that you're losing. It's a Lo Taaseh/ negative commandmen.
In a related topic, there are many lessons that we learn from the Shulchan in the Mishkan. The Shulchan represents our own personal table; we invite guests to our table. The Rabbenu Bachye in Terumah 25,23 mentions the custom of the Hasidim of France who used the wood of their tables (that they used to serve their guests on) to create caskets for their burials.
This was to show that there's nothing that you're take with you, from all your food and all your drink and all your hard work, except the the Sedaka that you did and the guests you had at your table. That is what you're taking that with you. That's why they would literally create caskets out of their tables.
The sefer Sivtei Kohen Al HaTorah, written by a student of the Arizal, says that letters of the word Shulchan/שלחן are an acronym for
שמור לקבורה חסד נדבתך which means guard for your burial the kindness of your generosity-
Because all that money that you gave and all the guests that you have, that's what's going with you. That's what you are actually saving for yourself. The money you give is really what you take. This is an important outlook and an attitude.
The story is told about the great Kapishnitzer Rebbe. He once saw a poor man wearing a hat that was all smashed up, so he took his own new hat and gave it to this poor man.
One of the Hasidim asked, “You have many hats. Why do you have to give him a new hat?”
The Rebbe told him, “I saved myself a new hat because what I give away is what is really is coming back to me.” There's a similar story with Rabbi Sholom Schwadron. A poor man came to before him before Pesach. Rabbi Schwadron had a shirt that he had brought back from America to save for the holiday, and he gave that shirt to the poor person.
So that is our lesson of the Parasha, on the proper hashkafa of Emunah to have when you give Sedaka, B’Ezrat Hashem.