Shavuot Greenery and Floral Synagogue Decoration

The widespread Ashkenazic custom of spreading grasses and placing trees or green branches in the synagogue (and home) on Shavuot, commemorating the greenery at the foot of Mount Sinai (Exodus 19:13 — "the flock and cattle shall not graze"). The Vilna Gaon opposed the practice as resembling non-Jewish seasonal customs, and it was accordingly dropped in Lithuanian communities, creating a documented intra-Ashkenazic divergence. Sephardic communities observe a related but distinct custom using fragrant herbs and flowers. The Rema's codification carried the custom throughout Ashkenazic Jewry in Poland, Bohemia, Moravia, Hungary, and the German lands. The Vilna Gaon's opposition, recorded in the Biur HaGra, caused Lithuanian communities to discontinue the practice — making this one of the clearest documented cases of minhag divergence within Ashkenaz. Sephardic observance (fragrant herbs and roses, following the Ben Ish Hai, Baghdad, 19th c.) is parallel but independently rooted. The Shulchan Arukh HaRav (OC 494:14, R. Shneur Zalman of Liadi) confirms the Chabad-Ashkenazic continuation of the custom.