I heard the following amazing story directly from the mouth of the protagonist:
There is a Yid in Flatbush who has owned a wine store for many years, from which he makes a good living. One day, he heard a shiur about the importance of giving maaser. He went home and told his wife that from then on, he would keep an exact account of every dollar he made, and he would make sure to give 10% to tzedakah.
A few months later, another Yid opened a competing store right next door. The competitor put a lot of money into making a beautiful, fancy store in order to draw in many customers. This was a great cause of anguish to the first storeowner. He couldn’t understand how this could happen to him – how his entire livelihood could be put in jeopardy - right after he undertook to strictly give maaser.
Still and all, he went home and told his wife, “This is a nisayon from Hashem. We need to continue giving maaser and having emunah, even if things look bleak.”
Over time, he began to lose customers. People preferred the fancy new store, and they began shopping there. The first storeowner’s nisayon got harder as he felt the loss in his income, but he continued giving maaser from whatever profits he had.
A short while later, he was walking past the new store when he noticed a “For Sale” sign hanging in the window. He went inside and asked the owner what was going on, and the man told him that he had borrowed a fortune of money from the bank to build his store, and he simply wasn’t making enough profit to pay back his loans. Therefore, he was forced to sell. He added that since he had to sell immediately or risk foreclosure, he was prepared to sell the building and the business to anyone who would pay him enough to repay his debt to the bank, even though this would mean that he would not be able to recoup all the extra money he had spent on beautifying the store. This meant that the owner was ready to sell the store and everything in it for 40% of its full value – which was a tremendous bargain.
The first storeowner saw this as a clear sign of Siyata D’Shmaya, and he purchased the business. He now understood that everything that looked bad for him was actually for his benefit. He now knew that as soon as he started giving maaser, Hashem began building a new business opportunity for him, and He even appointed a shliach to build it on his behalf and to put in all the necessary effort and monetary investment.
And now that he had his new state-of-the-art store, he began to earn 20 times as much profit as before.
We see from this story that even when a person faces what seems to be a difficult nisayon, he should know that Hashem sent it as his yeshua.