‘Now there were some present at that very season who told him of the Galileans, whose blood Pilate had mingled with their sacrifices.'
Hot news has arrived from Jerusalem of Pilate's latest atrocity. Galileans offering their sacrifices in the Temple (anything from two upwards) have at the very time of their bringing their sacrifices been slain in the Temple courtyard on Pilate's orders. We have no details of this particular occurrence, but it is typical of Pilate. It may be that they had already been marked men, and that Pilate had simply been waiting for them to arrive at the Temple where he could be sure of finding them at the particular feast, or it may be that while in the Temple they were seen as having fermented trouble resulting in a quick and merciless reaction.
The vivid language may not be intended absolutely literally. If they had brought their sacrifices and were waiting for them to be offered, rather than offering them themselves, it would equally apply. Indeed had their blood actually landed on the altar the incident would probably have become even more serious, for it would have been seen as the vilest of sacrilege.
Why the informers told Jesus is not explained. It may be that they hoped to stir Jesus up to supporting retaliatory action, or to trap Him into saying something unwise against the authorities. Or it may be that they were citing them as an example of the kind of people in mind in Luke 12:57-59, who having not become reconciled with God have received their just deserts. But whatever the motive it would appear that someone had suggested that their manner of death clearly indicated their special sinfulness.