‘And the disciples, every man according to his ability, determined to send relief to the brethren who dwelt in Judea, which also they did, sending it to the elders by the hand of Barnabas and Saul.'
So the disciples in Antioch, who would be far less affected by such a famine, and some of whom had the resources to prevent themselves from being too affected, determined to send help to those who lived in Judaea, whom they had gathered would be badly affected by the famine. Thus they gathered together funds, with each giving according to his ability, and sent it to the elders of the Judaean churches by the hand of Barnabas, whom the church of Jerusalem had sent to them, and Saul, Barnabas' co-worker. As the senior elder Barnabas is mentioned first. This would be Saul's second visit to Jerusalem as described in Galatians 2.
This was not, of course, just a matter of taking a collection and sending it off. It would take some time for them to get together what was being given, and then to organise it and send it on. And they may then have waited until the famine in question actually began.
‘The elders.' In a town or city those who were chosen from among their compatriots to have authority in the city and pass judgment in the gate were called ‘elders'. It was the name by which the leaders of the tribes of Israel were known when Moses went to them. It probably originally arose in the distant past because those who were chosen to have authority over tribes or cities tended to be the older, wiser and more experienced men, but in the end it applied to all who shared authority. Thus the organisers and planners who ran the synagogues were called ‘elders', and here it simply indicates the static leaders of the churches of Judaea.