הלכה אויף רות 1:16

People are accustomed to reading the Song of Songs on the Festival of Matzot because it speaks about the salvation from Egypt, which is the beginning of the subjugation of Israel and their first redemption. As it is stated (Song of Songs 1:9), "To a mare in Pharaoh’s chariots." And they are also accustomed to read Ruth on the Festival of Weeks (Shavuot), because it is written in it (Ruth 1:22), "at the beginning of the barley harvest" - and [Shavuot] is the the time of the harvest. And there is another reason: Because our ancestors only accepted the Torah and entered the covenant through circumcision, immersion and the sprinkling of blood [at that time], as it is found in the chapter [entitled] HaCholetz; and Ruth also converted, as it is stated (Ruth 1:16), "for where you go, I shall go." And from the answer of Ruth, we know what Noami said to her. As she said to her, "It is prohibited for us [to go beyond] the Shabbat perimeter." [She answered,] "Where you go, I shall go" (Ruth 1:16). "Isolation [with a stranger of the opposite sex] is forbidden to us." "Where you lodge, I shall lodge" (Ruth 1:16). "We are commanded to observe six hundred and thirteen commandments." "Your people are my people" (Ruth 1:16). "Idolatrous worship is forbidden to us." "Your God is my God" (Ruth 1:16). "Four types of capital punishment were handed over to the court." "Where you die, I shall die" (Ruth 1:17). "Two burial grounds were set up for the court, one for those burnt and stoned and another for those executed and strangled." "And there I shall be buried" (Ruth 1:17). So is it found in the chapter [entitled] HaCholetz (Yevamot 47b). And we are hence accustomed to reading Ruth on the Holiday of Weeks. And also on the Festival of Shemini Atzeret (Assembly of the Eighth), it is customary to read Ecclesiastes, because in it, it is written (Ecclesiastes 11:1), "Distribute portions to seven or even to eight" - these [correspond to] the seven days of the Festival (Sukkot) and the Festival of the Assembly of the Eighth. I mean to say, because it is the holiday of the reaping, to warn about the tithes and the priestly tithes and the pledges, such that they not transgress, "you shall not delay," [past] the three festivals. And there is another reason - because King Shlomo said it on the Festival (Sukkot) during the assembly (hakhel). As it is written (Deuteronomy 31:10-12), "at the appointed time of the year of remission, during the Sukkot festival; When all of Israel comes to be seen, etc. Assemble (Hakhel) the people; the men and the women and the infants, etc." And it is [also] written (I Kings 8:2), "they assembled before King Shlomo in the month of Etanim during the festival, etc." So he said it then in the assembly, to rebuke Israel. Hence it is fit to say it during [this] festival. All of this was written by Ibn HaYarchi (R. Avraham ben Natan). And they said in Tractate Soferim (14:3), "One who reads from Ruth, the Song of Songs, Lamentations and from the Scroll of Esther must [recite the blessing that concludes], 'concerning the reading of the Megillah' - even though it is included in the Writings. One who reads from the Writings must recite, 'Blessed are You, Lord our God, King of the universe, [who has sanctified us with Your commandments and has commanded us] to read in the Holy Writings.'"