Midrash su Salmi 113:1

Our Rabbis were taught: Forty-eight prophets and seven prophetesses preached to Israel, and subtracted or added nothing to our Torah, even not as much as one letter, save the reading of the Megilla, which was instituted by the prophets alone. What basis had they for that? R. Chiya b. Abbin, in the name of R. Joshua b. Karcha, said: "They drew a fortiori conclusion: If when Israel was delivered merely from slavery to freedom, they sang, how much more ought they do se when they were saved from death to life! If so, then why do we not say Hallel on Purim? "Because," said R. Isaac, "we do not say Hallel for the miracles that happened outside of Palestine." But the exodus from Egypt was also a miracle outside of Palestine? The reason for saying Hallel then is explained in the following Baraitha: Until Israel entered Canaan, they said praises for all miracles, but after they had occupied Palestine, they sang praises only for miracles in Palestine. R. Nachman b. Isaac, however, said: "The reading of the Megilla, is equivalent to the Hallel." Rab said: "There, when they went out of Egypt, it was right to say Hallel, because it is said. Praise, O ye servants of the Lord, and not Pharaoh's; but how could they say on Purim, Praise, O ye servants of the Lord. Were they not still the slaves of Ahasuerus?"

... Teach us, our master, from when does the mitzvah of the Channukah lamp begin? Our rabbis taught – from when the sun sets until the majority of people are gone from the marketplace. And where are they to be lit? If one lives on an upper floor with a window facing the public domain, light there. If it is a time of danger, light within your house [and it is forbidden to do work by its light. R’ Asi said] it is forbidden to see by its light. Why do we light Channukah lamps? When the Hasmonean High Priest defeated the Greeks, as it says “For I bend Judah for Me like a bow; I filled [the hand of] Ephraim, and I will arouse your children, O Zion, upon your children, O Javan; and I will make you as the sword of a mighty man,” (Zechariah 9:13) they entered the Holy Temple. They found there eight iron stakes, fixed them in the ground and lit lamps upon them. Why do we read the Hallel psalms of praise? Because it is written “The Lord is God, and He gave us light.” (Tehillim 118:27) Why don’t we read it on Purim? It is written “…to destroy, to slay, and to cause to perish the entire host of every people and province that oppress them…” (Esther 8:11) and we don’t read it except to mark the fall of a kingdom and the kingdom of Ahasuerus still stood. But when the Holy One destroyed the kingdom of Greece they began to sing hymns and praises and to say that in the past we were servants to Pharoah, servants to Greece and now we are servants to the Holy One “Praise, you servants of the Lord…” (Tehillim 113:1) How many channukot (dedications) were there? There were seven. The dedication of heaven and earth, as it says “Now the heavens and the earth were completed…” (Bereshit 2:1) What dedication was there then? “And God placed them in the expanse of the heavens to shed light upon the earth.” (Bereshit 1:17) The dedication of the wall, as it says “And in the dedication of the wall of Jerusalem…” (Nechemiah 12:27) The dedication of those who came up from the exile, as it says “And they offered up for the dedication of this House of God…” (Ezra 6:17) The dedication of the priests, which we light for. The dedication of the world to come, as it says “And it shall come to pass on that day, that I will search Jerusalem with candles…” (Tzephaniah 1:12) The dedication of the princes “This was the dedication offering of the altar…” (Bamidbar 7:84) The dedication of the Sanctuary, which this is speaking of “A psalm; a song of dedication of the House, of David.” (Tehillim 30:1) Another explanation. There are seven channukot. The dedication of the creation of the world, as it is written “Now the heavens and the earth were completed…” (Bereshit 2:1) Completion is the language of dedication, as is written “All the work of the Mishkan of the Tent of Meeting was completed…” (Shemot 39:32) The dedication of Moshe, as it is written “And it was that on the day that Moses finished erecting the Mishkan…” (Bamidbar 7:1) The dedication of the House, as it is written “A psalm; a song of dedication of the House, of David.” (Tehillim 30:1) The dedication of the Second Temple [as it says “And they offered up for the dedication of this House of God…” (Ezra 6:17) and the dedication of the wall] as it says “And in the dedication of the wall of Jerusalem…” (Nechemiah 12:27) The current one of the House of Hasmonean. The dedication of the world to come, because even that has lights, as it is written “And the light of the moon shall be like the light of the sun, and the light of the sun shall be seven-fold as the light of the seven days…” (Isaiah 30:26)