| Holiday Name: | Isru Chag |
| Official Name: | Hebrew: אסרו חג English translation: 'Bind the Festival' |
| Begins: | The night immediately following the Three Pilgrimage Festivals |
| Ends: | At nightfall of the day following the Three Pilgrimage Festivals |
| Observances: | Minor: Most omit tachanun from shacharit and mincha, and some partake of extra food and drink. |
| Type: | Jewish |
| Significance: | Follows each of the Three Pilgrimage Festivals. It serves to bridge the respective holidays for the rest of the year. |
Isru Chag (Hebrew: אסרו חג||Bind [the] Festival) refers to the day after each of the Three Pilgrimage Festivals in Judaism: Passover, Shavuot and Sukkot.
The phrase originates from the verse in Psalms 118:27, which states, “Bind the festival offering with cords to the corners of the altar.” This verse, according to the sages of the Talmud, should homiletically be understood to mean, “Whosoever makes an addition to the Festival by eating and drinking is regarded by Scripture as though he had built an altar and offered thereon a sacrifice.”[1]
In a responsum to a community that had inquired as to the rationale behind the observance of Isru Chag, Rabbi Yosef Hayyim (1832–1909), known as the Ben Ish Chai, cited Isaac Luria (1534–1572), the founder of Lurianic Kabbalah, to the effect that Jews connect the day after the holiday to the holiday itself due to the remaining “light” of the holiday – in other words, so that the sanctity of the holiday will be extended.[2]
Adding a degree of festivity to the day as a practice has further been codified in Ashkenazic communities, as Moses Isserles (1520–1572) has stated in his glosses on the Shulchan Aruch in the section Orach Chayim:
Yisrael Meir Kagan (1838–1933) ruled that the minhag (custom) is to generally forbid fasting on Isru Chag, except in instances when as a result of great distress the community synagogue decrees it.[3]
Almost all communities omit tachanun (additional prayers of supplication) on Isru Chag.[4] However, communities that follow the rulings of Maimonides (1135–1204), such as the Dor Daim (a movement founded in 19th century Yemen), maintain that the only days on which Tachanun is to be omitted are Shabbat, Jewish holidays, Rosh HaShanah, Rosh Chodesh, Hanukkah, Purim, and the mincha on the eve of any Shabbat and holiday.[5]