Where does “sajonara” come from?

sajonara (Polish) comes from Japanese さようなら, from Japanese 左様ならば, from Japanese ならば, from Japanese ば, from Japanese は, from Old Japanese は.

sajonara (Polish): sayonara, farewell

Definitions

Step	Language	Word	Meaning
1	Japanese	さようなら	a final expression of departure; farewell, so...
2	Japanese	左様ならば	—
3	Japanese	ならば	if
4	Japanese	ば	In Modern Japanese, attaches to the kateikei, and...
5	Japanese	は	what about, where is; Inserted between two verbs...
6	Old Japanese	は	—