—while he was standing on the planks of his pulpit—
“Let people desist from abandoning the Friday congregational prayers, or Allah will place a seal upon their hearts; then they will surely be counted among the heedless.” Narrated by Muslim.

1151 – Ibn ʿUmar (may Allah be pleased with him) reported that the Messenger of Allah (peace and blessings be upon him) said, “When any one of you comes to the Friday prayer, let him bathe.” Agreed upon.

1152 – Abu Saʿīd al-Khudri (may Allah be pleased with him) reported that the Messenger of Allah (peace and blessings be upon him) said, “The Friday bath is obligatory upon every adult.” Agreed upon.

In this context, “adult” means one who has reached puberty, and the “obligation” here is an emphatic recommendation—similar to a man saying to his companion, “Your right is incumbent upon me.” Allah knows best.