Yes, just as there were many eyewitnesses of Moses going up to Har Sinai and bringing back the Torah, so there were for Yeshua dying, rising from the dead, and ascending to heaven. Even Eliyahu had a witness of his ascendancy into heaven in the fiery chariot.
Do you believe the Tanakh without the oral law/commentaries, or is your belief system predicated on having the oral law too so that you cannot understand or believe the Holy Scriptures in and of themselves ?
I believe the Jews were given, 3326 years and five days ago, 2 sapphire, square (not like the rounded and oft-depicted ones Charlton Heston brought down) tablets upon which were written the 10 commandments for Jews (ahem, in Hebrew,) and then 40 days, one highly misunderstood golden calf incident (and broken aforementioned tablets,) and another 80 days later... a complete written and oral Torah via Moses our prophet...and a brand new set of sapphire tablets to boot, this time carved by Moses and engraved by G-d Himself.
The Books of Moses absolutely cannot be understood by themselves. Here is a link to some collated proofs of this fact, but in broad brush, there are many life-death (sentence) situations where G-d commands us to do or not to do something and then doesn’t explain it. (ie, “work” on the Sabbath.) Wouldn’t our benevolent Creator bother to tell us what He is talking about— with great, exacting detail? Can I light a fire on the Sabbath? No, it says so explicitly. Great. Can I move a sofa in my living room? It’s life or death— I better have a ready-answer...
http://www.aishdas.org/student/oral.htm