Sforno on Exodus 18:19/ספורנו על שמות י״ח:י״ט

1היה אתה לעם מול האלוקים, be their intermediary to advise the people of the various commandments G’d wants them to perform.

2והבאת אתה את הדברים אל האלוקים, An example of such a case is presented in Numbers 9,8 as well as in Numbers 27,5 where Moses submitted a problem to which he did know the answer to G’d before communicating the answer he received to the people afterwards.