[Diamond]

But there wasn't any commandment to "sabbath" or refrain from work on the new moons

Why then did the Jews ask in Amos 8:5,
"When will the new moon be gone, that we may sell corn? and the Sabbath, that we may set forth wheat?"

Cordially,

[DouglasKC]

Why then did the Jews ask in Amos 8:5, "When will the new moon be gone, that we may sell corn? and the Sabbath, that we may set forth wheat?"

I would guess tradition. They were extra careful to observe physical laws even going so far as to institute non-biblical measures. But again there is no command by the Lord to keep the new moons as a sabbath or to refrain from work.