Nedarim 50A

דלי ציפתא ואמר ליה לשלוחא: חזי מאי איכא. מיהו, לא ניחא לי דאיתהני בהדין עלמא.

He lifted the mat [tzifeta] upon which he was sitting and said to the messenger: See what there is here. The place was miraculously filled with gold dinars. This demonstrated that R' Yehuda could have had plenty of money if he had so desired. He explained: However, it is not amenable to me to derive benefit in this world.

רבי עקיבא איתקדשת ליה ברתיה (דבר) דכלבא שבוע. שמע (בר) כלבא שבוע, אדרה הנאה מכל נכסיה. אזלא ואיתנסיבה ליה.

§ In connection to the above incident concerning the poverty of scholars and their potential to become wealthy through remarkable circumstances, the Talmud relates an incident: R' Akiva became betrothed to the daughter of bar Kalba Savua. When bar Kalba Savua heard about their betrothal, he took a vow prohibiting her from eating all of his property. Despite this, she went ahead and married R' Akiva.

בסיתוא הוה גנו בי תיבנא, הוה קא מנקיט ליה תיבנא מן מזייה. אמר לה: אי הואי לי, רמינא ליך ירושלים דדהבא. אתא אליהו אידמי להון כאנשא וקא קרי אבבא. אמר להו: הבו לי פורתא דתיבנא דילדת אתתי, ולית לי מידעם לאגנויה. אמר לה רבי עקיבא לאנתתיה: חזי גברא דאפילו תיבנא לא אית ליה.

In the winter they would sleep in a storehouse of straw, and R' Akiva would gather strands of straw from her hair. He said to her: If I had the means I would place on your head a Jerusalem of Gold, a type of crown. Elijah the prophet came and appeared to them as a regular person and started calling and knocking on the door. He said to them: Give me a bit of straw, as my wife gave birth and I do not have anything on which to lay her. R' Akiva said to his wife: See this man, who does not even have straw. We should be happy with our lot, as we at least have straw to sleep on.

אמרה ליה: זיל הוי בי רב. אזל תרתי סרי שנין קמי דרבי אליעזר ורבי יהושע. למישלם תרתי סרי שנין קא אתא לביתיה, שמע מן אחורי ביתיה דקאמר לה חד רשע לדביתהו: שפיר עביד ליך אבוך חדא דלא דמי ליך. ועוד: [שבקך] ארמלות חיות כולהון שנין. אמרה ליה: אי צאית לדילי ⁠— ליהוי תרתי סרי שנין אחרנייתא. אמר: הואיל ויהבת לי רשותא, איהדר לאחורי. הדר אזל הוה תרתי סרי שני אחרנייתא.

She said to him: Go and be a student of Torah. He went and studied Torah for 12 years before R' Eliezer and R' Yehoshua. At the completion of the 12 years, he was coming home when he heard from behind his house that one wicked person was saying to his wife: Your father behaved well toward you. He was right to disinherit you. One reason is that your husband is not similar to you, i.e., he is not suitable for you. And furthermore, he has left you in widowhood in his lifetime all these years. She said to him: If he listens to me, he should be there for another 12 years. R' Akiva said: Since she has given me permission through this statement, I will go back and study more. He turned back and went to the study hall, and he was there for another 12 years.