What is the meaning of 豫兮 in 豫兮若冬涉川 ? A random phrase from the 道德經 is 豫兮若冬涉川 .

I understand the part 若冬涉川 as "like crossing a stream in the winter" where "in the winter is used" is used adverbially, so a more verbatim translation might be "like winter-walking a stream"

I looked up the first characters as:


豫  relaxed
兮  character that marks an exclamation (maybe like a pronounced ! ) 


But I cannot make any sense when combining both parts, the only translation I can come up with would be:

relaxed yo ! like winter-walking the stream

which does not make sense to me, because it feels paradox .
You must know that the character 豫  means being caution， being extremely careful;
兮 is modal particle， like 啊.

So,the whole sentence means (他)犹豫小心，就如同冬天过河一样，不敢贸然下水似的. Being extremely caution so that he dare not cross the river in winter.