Where does “だから” come from?

だから (Japanese) comes from Japanese だ, from Japanese である, from Japanese で, from Japanese ぜ, from Japanese ぞえ, from Japanese え, from Middle Chinese 衣.

だから (Japanese): Used other than with a figurative or idiomatic...

Definitions

Step	Language	Word	Meaning
1	Japanese	だ	Following parts of speech that do not inflect by...
2	Japanese	である	To be: the copula, with the same function as だ ...
3	Japanese	で	at; with, by, using; indicating the following...
4	Japanese	ぜ	sentence-ending particle signifying emphasis,...
5	Japanese	ぞえ	—
6	Japanese	え	Alternative form of い
7	Middle Chinese	衣	—

だから — Etymology, Origin & Word History | Etymology Explorer