Do you know why they needed to pray that the flight wouldn't be on a sabbath? Because they didn't have enough sense to obey the spirit of law and most of them wouldn't have had the sense to leave for fear of breaking "laws".
Mat 24:1 And Jesus went out, and departed from the temple:
and his disciples came to him for to show him the buildings of the temple.
Mat 24:2 And Jesus said unto them, See ye not all these things? verily I say unto you, There shall not be left here one stone upon another, that shall not be thrown down.
Mat 24:3 And as he sat upon the mount of Olives,
the disciples came unto him privately, saying, Tell us, when shall these things be? and what shall be the sign of thy coming, and of the end of the world?
So are you saying that the disciples would not obey the spirit of the law. If the Sabbath was to be null, Jesus would know that the disciples would realize and not be bothered. But that is not the case. The Sabbath is alive and well because it was the sabbath days added because of sacrifices and ordinances that were abolished and not the 7th day Sabbath. In a hasty attempt to respond to that question you seem not to remember or realize that Jesus was speaking to his disciples. But we all make mistakes
Yes, Jewish converts did keep the sabbath but it was generally so they could be where the people were to bear witness to Christ and spread the gospel.
History does not support that reason.
[FONT="]"The primitive Christians had a great veneration for the Sabbath, and spent the day in devotion and sermons. And it is not to be doubted but they derived this practice from the Apostles themselves, as appears by several scriptures to the purpose." "Dialogues on the Lord's Day," p. 189. London: 1701, By Dr. T.H. Morer (A Church of England divine).[/FONT]
[FONT="]"...The Sabbath was a strong tie which united them with the life of the whole people, and in keeping the Sabbath holy they followed not only the example but also the command of Jesus." "Geschichte des Sonntags," pp.13, 14[/FONT]
[FONT="]"The seventh-day Sabbath was...solemnised by Christ, the Apostles, and primitive Christians, till the Laodicean Council did in manner quite abolish the observations of it." "Dissertation on the Lord's Day," pp. 33, 34[/FONT]
[FONT="]"The ancient Christians were very careful in the observance of Saturday, or the seventh day...It is plain that all the Oriental churches, and the greatest part of the world, observed the Sabbath as a festival...Athanasius likewise tells us that they held religious assembles on the Sabbath, not because they were infected with Judaism, but to worship Jesus, the Lord of the Sabbath, Epiphanius says the same." "Antiquities of the Christian Church," Vol.II Book XX, chap. 3, sec.1, 66. 1137,1138.[/FONT]
[FONT="]"The primitive Christians did keep the Sabbath of the Jews;...therefore the Christians, for a long time together, did keep their conventions upon the Sabbath, in which some portions of the law were read: and this continued till the time of the Laodicean council." "The Whole Works" of Jeremy Taylor, Vol. IX,p. 416 (R. Heber's Edition, Vol XII, p. 416).[/FONT]
I have much more.