Today's sermon offers worshippers tips on purifying their souls and warns them against falling into evil.
"The human self flips between good and evil ... and in its nature it usually leans towards temptation and swerves away from guidance," the sermon says.
"The soul enjoineth unto evil, save that whereon my Lord has mercy," the sermon continues, citing the Quran. "Therefore, there is an urgent need to fix [the self] by purifying it."
The sermon explains that purifying the self - one of the goals of the prophets - involves steering it away from that which is prohibited and curing it from its sickness and love for sin. The self must be both observed and prosecuted, says the sermon.
Huda Moussa, a 54-year-old former business teacher from the Palestinian Territories, said that whenever she caught herself gossiping about people behind their backs, she felt her self had been "polluted".
"When I realise this feeling, I try to mention this person positively as much as I can to compensate for what I said," she said.
"I also give money to charity and do good deeds and repent - which we usually do - but with the intention that I want to make up for that specific sin."