That + Which

[Volcano1985]

Abhor that which is evil; cleave to that which is good.

1.Why does which come after that? Is only which not enough?

2.What does the sentence mean?

[engee30]

Abhor that which is evil; cleave to that which is good.

1.Why does which come after that? Is only which not enough?

2.What does the sentence mean?

In Old English, that which is equal to the Modern English what.

[MrPedantic]

In contemporary English too! Often you can disentangle the meaning of "what" by substituting "that (thing) which".

MrP