Resources for Kesubos 97
1. The גמרא discusses a case where someone sells a property so they can buy another item and then after the sale finds out that the item they were trying to buy is no longer available. The מסקנא is he can be חוזר on the sale. תוספות in ד"ה זבין explains that we must be talking about a case where the מוכר said they were selling their land for that reason because otherwise we have a rule of דברים שבלב אינם דברים. The problem is that there are cases where we pasken that nothing needs to be said. תוספות explains there are three types of cases: there are cases where you don’t need to say anything at all is because it is so glaringly obvious that nothing needs to be said (אומדנא דמוכח); there are cases where something needs to be said but no official תנאי needs to be made because it is a typical thing to do like to sell land to buy something else; and there are cases where what you say is unusual like selling clothes so you can move to another country in which case an official תנאי with the rules of בני גד ובני ראובן need to be followed. The תוספות רי"ד in קידושין on דף מ"ט ע"ב says the cases where nothing needs to be said are all cases of מתנה since we say דברים שבלב הוי דברים by a gift.
It seems clear that the various stages are to see what the seller or buyer was thinking at the time of the sale and depending upon how obvious it is we will have different requirements. The מרדכי in אות רנ"ד says in the name of the יראים that it is not all about figuring out what the person thought. If that were the case then one would never be bound by the rules of תנאי בני גד ובני ראובן. If someone only said a לשון תנאי and even expressed both sides of the תנאי but put the הן קודם ללאו, are we at all מסופּק what he was thinking? Of course not! Obviously he wants the condition to be in effect. Rather, thoughts can never be מבטל words even if we know for certain what he was thinking, and if you make a non-valid תנאי its as if nothing was said. The only time a person doesn’t need to say anything is in a case where its as if something was said. An example would be if you say you will sell something for 5,000 in America it is as if you said “dollars” because in normal conversation it doesn’t need to be said and its as if it was said since that’s how people talk. But אמדנא דמוכח is never valid. The ר"ן in קידושין דף מ"ט ע"ב in ד"ה ההוא says an incredible thing which is at odds with the מרדכי. The ר"ן says that if you don’t make a תנאי כפול we actually assume you meant to say that you don’t want the תנאי to be מקויים because why else would you say it the wrong way? That is exactly the opposite of the מרדכי who assumes your דעת is certainly to have the condition be valid.
2. תוספות in ד"ה לאתויי says that רש"י says that the חידוש of the case of ספק מגורשת is that she doesn’t collect מזונות from the יתומים. תוספות asks that it should be obvious that she couldn’t collect מזונות from the יתומים מספק. The הפלאה asks why is this פּשוט? Why isn’t this a case of someone who for sure owed money at one point and is מסופּק if they paid where they must pay מספק? The husband for sure owed her מזונות while he was alive, so this is just a ספק if that חיוב went away! He answers that תוספות must hold that each day comes with a new חיוב מזונות so from the time of death it’s a case of איני יודע אם נתחייבתי.