Mark 15:36

‘And one ran, and filling a sponge full of sour wine, put it on a reed and gave him it to drink, saying, “Let be. Let us see whether Elijah comes to take him down.” '

Previously the soldiers present had offered Him sour wine in mockery (Luke 23:36). This may thus be the continuation of the mockery. But more probably it was a sympathiser who genuinely believed that Elijah might come to save Him. The sour wine was a poor man's drink but if these had come to sympathise with One Whom they had previously admired they may well have brought wine with them, as the soldiers certainly would have (they knew that they had a long vigil, and wine dulled the sense of what they were doing. They were human too).

In view of the loud cry and the accompanying comments the soldiers may have been as interested in seeing whether something extraordinary might happen as the crowd, and thus not have interfered. The uncanny darkness had already brought home to them that this was not a run-of-the-mill execution.

‘Let be.' This may have been said to a Roman soldier who half-heartedly sought to interfere, meaning either ‘don't stop us' or ‘allow us to do this'. Or it may just be a general comment.

‘Gave Him it to drink.' It would seem He received it, which in itself suggested that His work was now complete and He could satisfy His thirst (see John 19:28).