SB 8.16.50
trayodasyam atho visnoh
snapanam pañcakair vibhoh
karayec chastra-drstena
vidhina vidhi-kovidaih
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Thereafter, following the directions of the sastra with help from brahmanas who know the sastra, on the thirteenth day of the moon one should bathe Lord Visnu with five substances [milk, yogurt, ghee, sugar and honey].