Have you ever heard of the Lunar Sabbath? Does the weekly cycle reset at the beginning of each month? Those teaching this concept, calculate the weekly Sabbath as resting upon the 1st, 8th, 15th, 22nd, and 29th of each lunar month.
Does this make any sense? How many days fall between the 29th and 1st? Based on the fourth commandment, is there an allowance for this span to vary? (cf. Exodus 20:8-11). Didn't God specify that work should be done for six days? I don't recall Him indicating how this number was subject to change every fifth span!
Arguably, the most popular proof text perpetuated by Lunar Sabbatarians is found within Exodus 16. They claim the supply of manna began on the 16th and continued through the 21st; thereby proving the Sabbath was the 22nd. Now admittedly, the weekly Sabbath may randomly fall upon the 22nd, but does it always? More importantly, did the weekly Sabbath really fall upon the 22nd in Exodus 16?
Notice the following chronology:
Verse 1) Israel arrived in the "wilderness of sin" on the 15th,
Verse 2) The people were hungry and complained,
Verse 7) Moses said the people would see the Glory of the Lord in the morning [meaning the 16th],
Verse 10) Just as Moses indicated, the Glory of the Lord appeared the morning of the 16th,
Verse 12) Then, the Lord said, "At twilight [that evening] you shall eat meat AND [following this] you shall have bread IN THE MORNING [of the 17th]",
Verse 22 then shares, "And it came to pass, that on the sixth day they gathered twice as much bread, two omers for each one, and all the rulers of the congregation came and told Moses."
Now, does this verse simply identify the sixth day [of the week] -or- the sixth [consecutive] day that manna fell?
Lunar Sabbatarians insist upon the latter. So, for the purpose of illustration, let's assume they are correct. Since we've already determined that manna began on the 17th, let's count another five days: 18th, 19th, 20th, 21st, and 22nd! Therefore, manna continued through the 22nd which they insist was a Sabbath!
In other words, the application of illogical Lunar Sabbath methodology fails the mathematical test of Exodus 16; which ironically is their largest proof text!