Bo 10:21 "V'yameish Hoshech"
Rashi says that, "k'mo v'ya'ameish...V'Onkelos Tirgeim l'shon hassarah k'mo
'Lo yamish'. "
If Targum Onkelos is miSinai, then how can Rashi argue that, "Ein hadibbur m'ushav al havav"
If Rashi MAY argue - then what does it mean to say Onkelos is MiSinai?