Ki Eshm'ra Shabbat is a popular Sabbath hymn, composed in the 12th-century by Abraham ibn Ezra. Though historically a song for Sabbath eve, today it is usually sung at Sabbath lunch. The hymn discusses which acts are appropriate, and which inappropriate, for the Sabbath. It contains five stanzas, the first letters of which spell the author's first name "Abraham" by acrostic. The refrain is "Because I will keep the Sabbath, God will protect me; it is an eternal sign between Him and me".