Even though the country where I live had been fighting two wars overseas for over a decade, I was never asked to ration my food. I’m not complaining. The prospect seems rather undesirable. But I remembered learning about how steel and some foods were rationed during the wars of the last century. I remember thinking that the act of every person’s purchases being rationed made everybody a part of the war effort. Rationing is not the same sacrifice as fighting and risking one’s life. But it is quite literally a form of “mesirus nefesh” giving away one’s comforts for the greater good of the community, the nation.
Like I said, there isn’t much need for this nowadays. But there are ways that even today we can flex that muscle of forgoing something for the “Kahal”, the public.
Forgoing that perfect parking spot if you are physically fit enough to walk a little farther; someone will appreciate the shorter walk more than you.
Paying a bill to a tzedaka ahead of the due date, because they can use the money sooner.
The imagination can conjure up other variations on this theme.