The Zera Shimshon (Beshalach 24) points out that when you spell out ס"נ in full like this: ך"סמ ן"נו, the added letters (called מילוי) also spell ס"נ. There is a second נ' in ן"נו, and the letters ך"מ in ך"סמ are gematria 60, the same as 'ס. So, within ס"נ, there is another ס"נ. He explains that when you praise Hashem for the miracle that occurred to you, you become a worthy candidate for another miracle.
The sefarim write this idea on the words (Tehillim 60:6) להתנוסס נס, one miracle draws down another one. Praising Hashem for the miracles makes us worthy of more miracles.
Many times, Chazal use the expression נס נס בתוך , one miracle within another miracle. The Zera Shimshon explains that this also alludes to our lesson. Within the miracle is the potential for additional miracles to develop.
He explains that therefore when one praises Hashem for miracles and he says birchas hagomel, the tzibbur replies כל שגמלך מי סלה טוב כל יגמלך הוא טוב . We are wishing unto him more miracles. This is because since he experienced one miracle, he has potential for more.
The Gemara (Brachos 54.) tells us that when Mar brei d'Ravina was in Arovos, he was thirsty, and miraculously, a well was created for him to quench his thirst. He was also in Riska d'Mechuza, and a wild camel attacked him there. Miraculously, a wall of a house fell, and he was able to save himself by running into the house.
The Gemara says that when he was in Riska d'Mechuza, he would say a brachah to praise Hashem for saving him from the camel and the thirst, and when he was in Aravos, he also praised Hashem for both miracles.
This is brought down in halachah. When a miracle happens to a person, and he returns to that place, he says the brachah שעשה ...ברוך הזה במקום נס לי , praising Hashem for the miracle that occurred. And if he experienced two or more miracles in his lifetime, when he praises Hashem for the miracles that occurred at that location, he should simultaneously praise Hashem for all his other salvations he experienced.
The Zera Shimshon explains that this is because all salvations are connected. When you praise Hashem for one salvation, it opens the channels for additional miracles. However, if he doesn't praise Hashem for a miracle, he is kafuy tovah and won't receive the next miracle.
There is also the concept of praising Hashem before the miracle occurred, and that will bring down the miracle he is waiting for.
The Midrash associates the words (25:2) תרומה לי ויקחו, "Take for Me a donation," with the words (Mishlei 4:2) לכם נתתי טוב לקח כי, "For I gave you good teaching." What is the connection? The Brezhaner Rav zt'l explains that these two pasukim teach us the same lesson. When one praises Hashem, even before the salvations come, he will merit yeshuos.
טוב לקח כי, if you want to receive good, לכם נתתי, think of it as if I have already given it to you. Therefore, לכם נתתי is written in past tense. Consider it like you have already received the goodness. This is also implied in תרומה לי ויקחו, Rashi writes לשמי לי. So תרומה לי ויקחו means if you elevate Hashem's name by praising Him, ויקחו, you take salvation for yourself.
The concept is that when you praise Hashem even before the salvation comes, you will merit to see it happen.
