Matthew 24:20

προσεύχεσθε, etc. (ἵνα μὴ with subjunctive instead of infinitive as often in N. T. after verbs of exhorting, etc.), pray that your flight be not in winter (χειμῶνος, gen. time in wh.) or on the Sabbath (σαββάτῷ, dat., pt. of time). The Sabbatarianism of this sentence is a sure sign that it was not uttered by Jesus, but emanated from a Jewish source, say many, e.g., Weizsäcker (Untersuchungen, p. 124), Weiffenbach (Wiederkunftsgedanke, i., p. 103) approving. But Jesus could feel even for Sabbatarians, if they were honest, as for those who, like John's disciples, fasted.