Who knows how many people Peter witnessed Jesus healing? No doubt quite a few, so he learned from the master. Jesus healed simply by command. Jesus knew it was the Father's will to heal people; so Peter knew it was the Father's will to heal people. Both acted out of complete faith, with no doubt of what the Father wanted done.
For reflection: How often am I able to act confidently, out of complete faith? Do I know that it is the Father's will to heal?
Let us pray. Father, sometimes I lack the faith to do the things I know you want done. Sometimes I am afraid of being ridiculed. Or I am just afraid of doing things "wrong". I am the one in need of healing today, Father. Heal me physically, spiritually, emotionally. Heal my unbelief.