غسل الجمعة
A recommended full-body wash before the Friday congregational prayer, described as an obligation upon every adult.
غُسْلُ الْجُمُعَةِ وَاجِبٌ عَلَى كُلِّ مُحْتَلِمٍ
“Friday's ritual bath is obligatory upon every adult.” (meaning, not a literal translation)
Commentators note the practical hygiene benefit of a guaranteed weekly full wash in a society without daily home bathing infrastructure — alongside its ritual purpose.