I do not understand exactly what you mean by a ceremonial sign. But the Sabbath Law is distinct from the ceremonial laws. Remember that with the ceremonial system everything has to do with sacrifices. On the monthly sabbaths special sacrifices were offered. God's holy Sabbath was not related to the offering of Sacrifices in anyway.
Actually, there were special sacrifices offered on the Sabbath, in addition to the regular daily offerings:
Num 28:1 And the LORD spoke unto Moses, saying,
Num 28:2 Command the children of Israel, and say unto them, My offering, and my bread for my sacrifices made by fire, for a sweet savor unto me, shall ye observe to offer unto me in their due season.
Num 28:3 And thou shalt say unto them, This is the offering made by fire which ye shall offer unto the LORD; two lambs of the first year without spot day by day, for a continual burnt offering.
Num 28:4 The one lamb shalt thou offer in the morning, and the other lamb shalt thou offer at even;
Num 28:5 And a tenth part of an ephah of flour for a meat offering, mingled with the fourth part of a hin of beaten oil.
Num 28:6 It is a continual burnt offering, which was ordained in mount Sinai for a sweet savor, a sacrifice made by fire unto the LORD.
Num 28:7 And the drink offering thereof shall be the fourth part of a hin for the one lamb: in the holy place shalt thou cause the strong wine to be poured unto the LORD for a drink offering.
Num 28:8 And the other lamb shalt thou offer at even: as the meat offering of the morning, and as the drink offering thereof, thou shalt offer it, a sacrifice made by fire, of a sweet savor unto the LORD.
Num 28:9 And on the sabbath day two lambs of the first year without spot, and two tenth deals of flour for a meat offering, mingled with oil, and the drink offering thereof:
Num 28:10 This is the burnt offering of every sabbath, beside the continual burnt offering, and his drink offering.
Num 28:11 And in the beginnings of your months ye shall offer a burnt offering unto the LORD; two young bullocks, and one ram, seven lambs of the first year without spot;
Num 28:12 And three tenth deals of flour for a meat offering, mingled with oil, for one bullock; and two tenth deals of flour for a meat offering, mingled with oil, for one ram;
Num 28:13 And a several tenth deal of flour mingled with oil for a meat offering unto one lamb; for a burnt offering of a sweet savor, a sacrifice made by fire unto the LORD.
Num 28:14 And their drink offerings shall be half a hin of wine unto a bullock, and the third part of a hin unto a ram, and a fourth part of a hin unto a lamb: this is the burnt offering of every month throughout the months of the year.
Num 28:15 And one kid of the goats for a sin offering unto the LORD shall be offered, beside the continual burnt offering, and his drink offering. (KJV)
PROPHECYKID said:
We know that the 7th day Sabbath was not observed like the monthly sabbaths in terms of sacrifices and so on.
Yes, it was, according to Numbers 28.
Also, Jesus said that the priests in the temple profaned the Sabbath and yet were blameless:
Mat 12:5 Or have ye not read in the law, how that on the sabbath days the priests in the temple profane the sabbath, and are blameless
Mat 12:6 But I say unto you, That in this place is one greater than the temple.
Mat 12:7 But if ye had known what this meaneth, I will have mercy, and not sacrifice, ye would not have condemned the guiltless.
Mat 12:8 For the Son of man is Lord even of the sabbath day. (KJV)
What do you think the priests were doing in the temple to profane the Sabbath?