Where does “不幸中の幸い” come from?

不幸中の幸い (Japanese) comes from Japanese 幸い, from Japanese sakiwai, from Japanese 幸, from Middle Chinese 幸.

Ancestry of “不幸中の幸い”, step by step

不幸中の幸い traces back through 3 separate lines of ancestry.

via Japanese 幸い

Step	Language	Word	Meaning
1	Japanese	幸い	very fortunate and happy, especially as bestowed...
2	Japanese	sakiwai	—
3	Japanese	幸	good luck, good fortune; happiness; an appearance...
4	Middle Chinese	幸	—

via Japanese の

Step	Language	Word	Meaning
1	Japanese	の	genitive case marker; nominative case marker in a...
2	Old Japanese	の	plain, field
3	Middle Chinese	能	talent, ability

via Japanese 中

Step	Language	Word	Meaning
1	Japanese	中	middle, medium; average; neither good nor poor;...
2	Japanese	中今	the present, as a privileged moment in eternity
3	Japanese	今	now; just now; soon

Every word from Middle Chinese 幸 →Every word from Japanese 幸 →Every word from Japanese sakiwai →