With all due respect, I believe it actually was.
Matt. 12:12
Matt. 24:20 - referring to a time after the LORD's ascension.
Mk.2:12 & 28
Acts 13:14, 27, 42, 44; 15:21, 16:13; 17:2; 18:4
Notice that the Apostles and the gentile congregants were all keeping the Sabbath after the ascension of the...