" Monks , I will teach you craving: the ensnarer that has flowed along, spread out, and caught hold, with which this world is smothered & enveloped like a tangled skein, a knotted ball of string, like matted rushes and reeds, and does not go beyond transmigration, beyond the planes of deprivation, woe, & bad destinations. Listen well, and I will speak."
"Yes, lord," the monks responded.
The Blessed One said: "And which craving is the ensnarer that has flowed along, spread out, and caught hold, with which this world is smothered & enveloped like a tangled skein, a knotted ball of string, like matted rushes and reeds, and does not go beyond transmigration, beyond the planes of deprivation, woe, & bad destinations? These 18 craving-verbalizations [1] dependent on what is internal and 18 craving-verbalizations dependent on what is external.
"And which are the 18 craving-verbalizations dependent on what is internal? There being 'I am,' there comes to be 'I am here,' there comes to be 'I am like this' ... 'I am otherwise' ... 'I am bad' ... 'I am good' ... 'I might be' ... 'I might be here' ... 'I might be like this' ... 'I might be otherwise' ... 'May I be' ... 'May I be here' ... 'May I be like this' ... 'May I be otherwise' ... 'I will be' ... 'I will be here' ... 'I will be like this' ... 'I will be otherwise.' These are the 18 craving-verbalizations dependent on what is internal.
"And which are the 18 craving-verbalizations dependent on what is external? There being 'I am because of this (or: by means of this),' there comes to be 'I am here because of this,' there comes to be 'I am like this because of this' ... 'I am otherwise because of this' ... 'I am bad because of this' ... 'I am good because of this' ... 'I might be because of this' ... 'I might be here because of this' ... 'I might be like this because of this' ... 'I might be otherwise because of this' ... 'May I be because of this' ... 'May I be here because of this' ... 'May I be like this because of this' ... 'May I be otherwise because of this' ... 'I will be because of this' ... 'I will be here because of this' ... 'I will be like this because of this' ... 'I will be otherwise because of this.' These are the 18 craving-verbalizations dependent on what is external.
"Thus there are 18 craving-verbalizations dependent on what is internal and 18 craving-verbalizations dependent on what is external. These are called the 36 craving-verbalizations. Thus , with 36 craving-verbalizations of this sort in the past, 36 in the future, and 36 in the present, there are 108 craving-verbalizations.
"This, monks is craving the ensnarer that has flowed along, spread out, and caught hold, with which this world is smothered & enveloped like a tangled skein, a knotted ball of string, like matted rushes and reeds, and does not go beyond transmigration, beyond the planes of deprivation, woe, & bad destinations."
See also: AN 4.200 .