Worshippers slept in packed tents outside the golden-domed mosque, waking before dawn to kneel on rows of prayer mats laid out in its cavernous central hall.
But unknown to the guests, the coronavirus was also passing among them.
The Muslim gathering held at the end of last month at a sprawling mosque complex on the outskirts of Malaysia's capital Kuala Lumpur has emerged as a source of hundreds of new coronavirus infections spanning Southeast Asia.