The Buddha explains to Saṅgārava that mantras learnt at a time when the heart is possessed by sensual lust, malevolence, sloth and torpor, excitement and flurry, doubt and wavering, are easily forgotten; as is the case of a man who tries to see his reflection in a bowl of water, either mixed with some dye, or heated on the fire, or overspread with mossy grass, or ruffled by the wind, or muddied and set in the dark. The cultivation of the seven factors of enlightenment (bojjhaṅga) will remove these disadvantages. S.v.121 ff; cf. No.5 below.