"All of Israel has a share in the World-to-Come". It is the Jewish custom to recite this Mishna before reading a Mishna or Halakha. The reason may be found in what our sages, of blessed memory, said: "Whoever supports Torah scholars is considered as though he studies, 'for to be in the shelter of wisdom is to be also in the shelter of money'. We learn from this that those who support Torah scholars are considered as though they, themselves, study because they enable Torah scholars to study and are rewarded as though they have fulfilled [the mitzvah].
This is what is meant by "All of Israel". 'All' – includes the supporters, which is why we always recite this Mishna before we study, indicating that the supporters are rewarded as though they themselves study, as the verse that follows shows, "And Your people are all righteous". Question: Are there not, however, some people who do not deal in Torah? But by supporting them and providing them with a livelihood, they share the reward and all are, therefore, righteous.