首楞嚴義疏注經 5.163

5.163

觀香悟道，得童真位，名為童子。初佛總教，觀有為相，不的言香。如云「一切有為法，如夢幻泡影，如露亦如電，應作如是觀。」

Contemplating fragrance and awakening to the Way, he attained the stage of youth purity (kumārabhūta), hence he is named 'Youth' (kumāra). Initially the Buddha gave general instruction to contemplate conditioned characteristics, without specifically mentioning fragrance. As it is said: 'All conditioned dharmas are like dreams, illusions, bubbles, and shadows; like dew and like lightning; one should contemplate them thus.'