Some have thought that Jesus' healings always
were instant but that is not true.

The nobleman's son "began to amend" from the
hour that Jesus spoke the word (John 4:52). Of
course there must have been other cases, like the
lepers being healed on their way to the priests.

Jesus' miracles were manifested by the same gifts
of the Holy Spirit which were operating in His
followers (John 14:12). He said that believers
would lay hands on the sick and they would get
well (Mark 16:18).