Midrash sa Isaias 58:10: Mekhilta DeRabbi Yishmael, Ein Yaakov (Glick Edition), Vayikra Rabbah & Midrash Tehillim

(Exodus 15:1) "Az yashir Mosheh": Az ("then") sometimes signals the past and sometimes signals the future. The past: (Genesis 4:26) "Az men began", (Exodus 4:26) "Az she said", (Exodus 15:1) "Az Moses sang", (Numbers 21:17) "Az Israel sang", (Joshua 10:12) "Az Joshua spoke", (I Chronicles 15:2) "Az David said", (I Kings 8:12) "Az Solomon said." And sometimes "Az" signals the future, viz.: Isaiah 60:5) "Az you will see and flow", (Ibid. 58:8) "Az your light shall break forth as the morning", "Then there shall be opened", (Ibid. 35:6) "Az the lame man shall leap as a hart", (Ibid. 5) (Jeremiah 31:12) "Az the virgin will rejoice in the dance", (Psalms 126:2) "Az our mouth will be filled with laughter", (Ibid.) "Az they will say among the nations."

We are taught in a Baraitha, R. Maier says: "If a common questioner discusses, 'If your God likes the poor, why then does He not sustain them?' answer him, 'for the purpose of saving us [through the charity] from the punishment of Gehenna.'" The same question did Tarnusruphus ask of R. Akiba: "If your God likes the poor, why then does he not sustain them?" And R. Akiba answered him: "For the purpose of saving us [through the charity] from the punishment of Gehenna." To which Tarnusruphus rejoined: "On the contrary, for this you deserve to be punished with Gehenna; and I will give you a parable from which you will understand why. A frail king who became angry at his slave and put him in prison, announced his desire that nobody should give him either food or drink. In spite of this, a person fed him and gave him drink. When the king becomes aware of it, would the king not be angry at that man? And ye Israelites are called servants, as it is written (Lev. 25, 55) For unto Me are the children of Israel servants." R. Akiba answered: "I will give you another parable, to which my previous answer is to be compared: A frail king became angry with his son, put him in prison, and commanded that nobody should give him either food or drink; in spite of this command, a man fed him and gave him drink. When the king became aware of it, would he not be grateful to this person and even send him a present? And we Israelites are called children, as it is said (Deut. 14, 1) Ye are the children of the Lord," etc. Tarnusruphus, however, said: "You are named children and also servants; i.e., children, when you are doing the Omnipotent's will, and servants when you act against the Omnipotent's will. And you will admit, that now you are acting against His will [since your Temple is destroyed and you are in exile].." R. Akiba answered: "With regard to this, the passage says (Is. 58, 10) Is it not to distribute thy bread to the hungry and the afflicted souls with the members of thy house. The afflicted souls [you will admit] refer to us in our present circumstances, and nevertheless, it says there, Is it not to distribute thy bread to the hungry?"

“And offer [your soul] to the hungry” (Isaiah 58:10); if you merit, [you will give] to the hungry of Jacob; if not, to the sated of Esau.³⁴If you do not contribute sufficiently to charity, your money will be confiscated by the non-Jewish authorities. In the time of the Sages, this was Rome, which is identified as a descendant of Esau. “And bringing home the wretched poor” (Isaiah 58:7), these are the poor from their youth.³⁵They present themselves as needy even though they are no longer poor. Some explain that this refers to the governmental authorities, who would demand payment as though they were poor, and were used to doing so as though a lifelong habit. Thus, if you do not “offer your soul to the hungry,” you will “bring home the wretched poor” (Etz Yosef). Rabbi Yitzḥak said: Like that blind person that they call full of light.³⁶It was common to euphemistically refer to a blind person as full of light. That is why it is stated: “And bringing home the wretched poor.” Alternatively, “and bringing home the wretched poor,” these are homeowners who lost their dignity and their property. What caused them to become impoverished? It is because they did not extend their hand to the poor and did not fulfill the will of their Father in heaven. That is why it is stated: “And bringing home the wretched poor.”³⁷Thus, the verses are understood to mean that if you do not “offer your soul to the hungry,” you will bring “the wretched poor” into your own home, meaning you will become poor. Alternatively, “wretched poor,” these are mourners and embittered souls, whose spirits are forlorn. What gladdens them? It is wine, as it is written: “Give intoxicating drink to the desolate and wine to embittered souls” (Proverbs 31:6). That is why it is stated: “And bringing home the wretched poor.”³⁸According to this interpretation, the verses address two different cases: One must provide basic sustenance to the poor, but this is not sufficient for mourners and the forlorn; one must bring them to one’s house, and provide them with wine.
Another matter, “and bringing home the wretched poor,” these are Torah scholars who enter the homes of the ignorant and saturate them with matters of Torah. That is why it is stated: “And bringing home the wretched poor.” Alternatively, “and bringing home the wretched poor,” these are Torah scholars and their disciples who teach Israel ritual impurity and purity, what is prohibited and permitted, and they teach them to perform the will of their Father in Heaven. That is why it is stated: “And bringing home the wretched poor.” Rabbi Avin said: Anyone who hosts a Torah scholar in his house, the verse ascribes it to him as though he offered first fruits. “Bringing [tavi]” is stated here, and “bring” is stated there: “You shall bring [tavi] to the house of the Lord your God” (Exodus 23:19). Just as there it is first fruits, so too, here, it is first fruits.