大乘百法明門論開宗義決 1.136

1.136

觸依彼生等者。此中彼者即是三和。觸因彼生者從因立名。因彼三和而生觸故。令彼和合者從果立名。謂因觸力三和合故。說為彼者釋上立名。釋前觸位三合名也。

Regarding 'Sparśa arises in dependence on that,' and so forth: 'that' here refers precisely to the tri-saṃnipāta. That sparśa arises due to that is a designation established from the cause, because sparśa arises on the basis of that tri-saṃnipāta. That it causes them to harmonize is a designation established from the effect, meaning that due to the power of sparśa, the three harmonize. Speaking of it as 'that' explains the above establishment of the name; it explains the earlier designation of the tri-saṃnipāta at the stage of sparśa.