I thought that helfen required Dative without any preposition, but in one of my favorite songs by J.S.Bach, the lyrics go like this:
Wir eilen mit schwachen, doch emsigen Schritten,
O Jesu, o Meister, zu helfen zu dir!
Is this usage normal? Still used today? Does it have the same meaning as without zu? Or was the zu just stuck there for meter's sake?