It is a mitzva to recite Hallel on special occasions, in order to thank and praise God for the miracles He performs on our behalf. First and foremost, we recite Hallel on the festivals that the Torah commands us to observe: Pesaĥ, Shavu’ot, and Sukkot, when we remember the miracles and acts of kindness that God performed for us when He took us out of Egypt, gave us the Torah, and brought us through the wilderness to Eretz Yisrael.

The Sages also instituted the recitation of Hallel on all eight days of Ĥanuka, as the beraita states:

Why did they see fit to require us to recite the complete Hallel on these days? To teach us that for every salvation God performs for Israel, they (the Jews) come before Him in song and praise. Accordingly, it says in the book of Ezra, “They responded with praise (hallel) and thanks to the Lord: ‘For He is good….’” (Megilat Ta’anit, ch. 9)

Similarly, the Talmud states that after the miracle of the splitting of the Red Sea:

The prophets among them instituted that the Jews should recite Hallel at every episode and for every trouble that does not befall them, and when they are redeemed they should recite it over their redemption. (Pesaĥim 117a)

Rashi explains that the Sages of the Second Temple era relied on this principle to institute the recitation of Hallel on Ĥanuka.

It follows that we must recite Hallel over the miracle that God performed for us on Yom Ha-atzma’ut. On that day we were saved from the worst hardship of all, that of exile and subjugation to foreigners, which caused all of the terrible suffering and massacres that we experienced for nearly 2,000 years.[6]

We must be very careful not to deny God’s benevolence, as the Sages say, “Whoever acknowledges a miracle done on his behalf will be privileged to have another miracle done for him.” Conversely, if we neglect to thank God, we will delay the redemption, God forbid. The Talmud relates that King Ĥizkiyahu was a very righteous man who spread Torah extensively throughout Israel, but difficult times eventually beset him. King Sennacherib of Assyria besieged Jerusalem with a mighty army, intending to destroy it, and Ĥizkiyahu fell deathly ill. Nevertheless, he did not lose faith; instead, he cried out to God, who performed a great miracle on his behalf, curing his illness and destroying Sennacherib’s entire army in one night. At that moment, God wanted to declare Ĥizkiyahu the Messiah, consider the war against Sennacherib the apocalyptic war of Gog and Magog, and bring redemption to the world. But Ĥizkiyahu did not sing songs of praise, i.e., Hallel, over his redemption. The heavenly attribute of justice said to God, “Master of the Universe, if You did not make King David of Israel, the Messiah, even though he uttered so many songs and praises before You, will You make Ĥizkiyahu the Messiah, seeing that he failed to sing songs of praise after You performed all of these miracles for him?” Therefore, the matter was sealed, and great sorrow spread throughout all the worlds. The earth wanted to sing songs of praise in Ĥizkiyahu’s stead, and the “minister of the world” wanted to defend him, but their pleas were rejected; the opportunity was lost. The prophet said, “Woe to me! Woe to me! Until when?” (San. 94a).

The same is true of us. For many generations we prayed, “Raise high the banner to gather our exiles” and “Swiftly, lead us upright to our land.” Now that our prayers have been answered, shall we not thank God? Similarly, it says, “Save us, Lord our God, and gather us from among the nations, that we may give thanks to Your holy name and glory in Your praise” (Tehilim 106:47). Now that He has gathered us, shall we not thank His holy name and sing His praise?