俱舍論頌疏論本 9.49

9.49

"When differences in the causes of the three feelings / are not yet understood, it is called contact": as for "the causes of the three feelings," this refers to the objects of the three feelings, for the objects are called causes because they can produce feeling. That is, after emerging from the womb up to two or three years of age, the faculty, object, and consciousness can have contact upon confronting one another; the five skandhas of this stage are collectively named contact. Because the characteristic of contact is prominent, it is designated with the name contact. Since one is not yet able to understand the objects of the three feelings, it is not yet called feeling.