Charles Spurgeon Commentary Matthew 10:7-8

"And as ye go, preach, saying, The kingdom of heaven is at hand. Heal the sick, raise the dead, cleanse the lepers, cast out demons: freely ye received, freely give." — Matthew 10:7-8 (ASV)

And as ye go, preach, saying, The kingdom of heaven is at hand. Heal the sick, cleanse the lepers, raise the dead, cast out devils: freely ye have received, freely give.

They were to be medical missionaries, preaching the gospel, and healing the sick, and it was all to be done "freely."