Our Gemara on Amud Aleph relates a teaching of Rebbe Yitschok: “One who finds a wallet on Shabbos may carry it in increments of less than four cubits.”

Rebbe Yitschok makes an allowance to violate rabbinic proscriptions because the fear of financial loss is too difficult for the average person. In order to forestall a greater violation, this exception is allowed (see Shabbos 153a).

This is not the only time Rebbe Yitschok makes judgments that combine psychology and finances. In Bava Metzia (21b), Rebbe Yitschok teaches that a person constantly checks his money bag. Therefore, if somebody finds money in the street with no identification, the rabbis allow the finder to keep it, since the original owner likely already realized it was lost and gave up hope, rendering it ownerless. Another financial teaching (ibid. 42a) offers practical advice about how to divide one’s assets to ensure some liquid and available.

A further discussion (ibid. 87a) touches on psychological and gender differences in generosity toward guests:

The verse states regarding Avraham’s direction to Sarah: “Make ready quickly three measures of flour, fine flour” (Bereishis 18:6). The Gemara asks about the apparent redundancy: “Flour” and “fine flour.” Rabbi Yitschok explains that from here we learn that a woman is more parsimonious with guests than a man. Sarah wanted to use ordinary flour, while Avraham persuaded her to use fine flour.

It is fascinating to see an Amora with several teachings focusing on financial and psychological dynamics. This last teaching requires analysis. What quality accounts for this difference between genders? It does not reflect well on Sarah at first glance, though ultimately she follows Avraham’s sensitivities, and perhaps that itself is positive—that spouses can influence each other.

Modern research, however, suggests women are often more charitable than men, possibly due to higher empathy (Mesch, Brown, Moore, Hayat, International Journal of Nonprofit and Voluntary Sector Marketing, Vol. 16, Issue 4). Yet psychology distinguishes between empathy for outsiders versus protectiveness within the home. Men and women both attach status to irrational markers—cars, titles, recognition. A woman may invest her identity more in the home and family. The Talmudic Aramaic word for wife is de-bis-hu (“of the house”). Thus, women might be more protective of the home, even if charitable outside it. Sarah herself declares (Bereishis 21:10): “Cast out that maidservant and her son…”—reflecting protection of family over hospitality.

Yaavetz (Bava Metzia 87a) interprets more gently: Avraham suspected Sarah might be less generous, but he left it to her choice, saying both “flour” and “fine flour.” She ultimately chose fine flour. Ben Yehoyada goes further: Avraham knew women generally are less generous with guests, but he also knew Sarah was exceptional. He gave her the opportunity to shine, confident she would choose fine flour herself.

These interpretations highlight an important marriage lesson: give your spouse space to make their own moral choices instead of sermonizing. That is solid relationship advice.