Lel Shimurim Oto El Hatzah information

Lel Shimurim Oto El Hatzah (Hebrew: ליל שמורים אותו אל חצה, literally 'The Night of Protection which God Split in Half') is a Maariv piyyut for the Maariv service on the first night of Passover (the seder night) of unknown authorship, which originated in the classical period of piyyut (6th-8th century). This piyyut was accepted in all the communities of Ashkenaz and Poland,^[1] France,^[2] Italy,^[3] Romania,^[4] Algeria,^[5] and also in the rites of Provence and Catalonia.^[6]

^ It appears in all manuscripts and printed editions of these rites (except for some very recent machzorim that have removed piyyutim entirely).
^ The piyyut does not appear in the printed Machzor Vitry, where a different two Lel Shimurim appear instead for the first two night. However, in the Reggio manuscript of Machzor Vitry, this piyyut appears for the first night, followed by the other two piyyutim. See Yonah Fraenkel, Machzor for Passover, Jerusalem 1993, page 22 in the introduction.
^ It appear in the 1486 and 1540 editions of this Machzor. In later editions, it does not appear.
^ Machzor Romania, Venice 1523, page 109b. Today, it is recited in Kehila Kedosha Janina, but before the blessings of Shema and not inside the blessings.
^ Yonah Fraenkel, Machzor for Passover, Jerusalem 1993, page 23 in the introduction.
^ Idan Peretz, Siddur Catalonia, Jerusalem 2019, page 392.

[1] It appears in all manuscripts and printed editions of these rites (except for some very recent machzorim that have removed piyyutim entirely).

[2] The piyyut does not appear in the printed Machzor Vitry, where a different two Lel Shimurim appear instead for the first two night. However, in the Reggio manuscript of Machzor Vitry, this piyyut appears for the first night, followed by the other two piyyutim. See Yonah Fraenkel, Machzor for Passover, Jerusalem 1993, page 22 in the introduction.

[3] It appear in the 1486 and 1540 editions of this Machzor. In later editions, it does not appear.

[4] Machzor Romania, Venice 1523, page 109b. Today, it is recited in Kehila Kedosha Janina, but before the blessings of Shema and not inside the blessings.

[5] Yonah Fraenkel, Machzor for Passover, Jerusalem 1993, page 23 in the introduction.

[6] Idan Peretz, Siddur Catalonia, Jerusalem 2019, page 392.