Galatians 2:12

Did eat with [σ υ ν η σ θ ι ε ν]. A. V. misses the force of the imperfect, marking Peter's custom. Not only at church feasts, but at ordinary meals, in defiance of the Pharisaic that this prohibition was not binding (Acts 10:28; Acts 11:8; Acts 11:9), and had defended that position in the apostolic conference (Acts 14:7 ff.).

Withdrew and separated himself [υ π ε σ τ ε λ λ ε ν κ α ι α φ ω ρ ι ζ ε ν ε α υ τ ο ν]. Or, began to withdraw, etc. Upostellein only here in Paul. It means, originally, to draw in or contract. Thus of furling sails, closing the fingers. Middle voice, to draw or shrink back from through fear. Hence, to dissemble or prevaricate. There seems to be no special reason for making it either a military metaphor, as Lightfoot, or a nautical metaphor, as Farrar. See on Acts 20:20.