The Greek preposition ater means without or apart from — expressing absence or separation. It appears in Luke 22:6 (Judas watched for a moment 'without a crowd' to betray Jesus) and Luke 22:35 (Jesus asking disciples about their earlier mission when He sent them 'without purse, bag or sandals').
The two uses of ater in Luke 22 form a profound contrast. Judas sought a moment ater ochlos — without the crowd — to betray Jesus in secret. Meanwhile, Jesus reminds the disciples how they lacked nothing when sent out ater material provision. One 'without' describes betrayal in darkness; the other describes miraculous divine provision in obedience. The contrast illuminates the whole of Luke 22: through faithlessness and betrayal, God provides salvation — the ultimate 'without' being that Christ died for us without our deserving it.