Did anyone equate the tathagatagarbha with the past?

This question may sound strange, but in my secular frustrations, I'm thinking about "the past" as some kind of ***womb*** which has nourished and given birth to "me" *now*. Do Buddhists, of any sort, have a name for **the past**? How does it feature in any doctrines of Buddhist salvation? Does anyone equate the past with the womb of the Tathagata?