"Now when they saw the boldness of Peter and John, and perceived that they were uneducated and untrained men, they marveled. And they realized that they had been with Jesus. And seeing the man who had been healed standing with them, they could say nothing against it. But when they had commanded them to go aside out of the council, they conferred among themselves, saying, 'What shall we do to these men? For, indeed, that a notable miracle has been done through them is evident to all who dwell in Jerusalem, and we cannot deny it. But so that it spreads no further among the people, let us severely threaten them, that from now on they speak to no man in this name.' So they called them and commanded them not to speak at all nor teach in the name of Jesus. But Peter and John answered and said to them, 'Whether it is right in the sight of God to listen to you more than to God, you judge. For we cannot but speak the things which we have seen and heard.' So when they had further threatened them, they let them go, finding no way of punishing them, because of the people, since they all glorified God for what had been done. For the man was over forty years old on whom this miracle of healing had been performed" (Acts 4:13-22).
Peter and John spoke with authority and great confidence (cf. Matt. 10:17-20). The members of the Sanhedrin were in awe of the boldness of Peter and John, particularly since they were neither highly educated nor trained for public speaking. Interestingly, the council realized the source of the apostles' boldness--"they had been with Jesus"! They could see the powerful influence Jesus had on these men through their speech and actions. Friends, what about you and I? Can people tell that we've been with Christ by the way we talk and behave? Although we have not been privileged to experience the earthly ministry of the Lord as the apostles did, we are still expected to cultivate the mind of Christ (cf. Phil. 2:5). We can do this with the word of God, prayer, and personal reflection. Others will be able to tell whether Jesus and His word have a deep impact on our lives or not.
It appears from Acts 4:14 that the man who had been healed had also been arrested with the apostles (or, at the very least, was allowed to join them for this hearing). His appearance before the council, however, only strengthens the case of Peter and John. The Sanhedrin couldn't think of anything to say against the miracle. Peter and John had done nothing wrong!
After dismissing the healed man and the apostles briefly, the council members discussed the situation privately. They realized they had a serious problem, and they're scrambling for a solution. They wanted to punish Peter and John to protect their own influence with the people, but, since all of Jerusalem knew of the good deed, this was not an expedient option. The miracle could not be denied, yet their hard hearts would not allow them to believe in Jesus! Since they had no valid rationalization to punish the disciples, they settle for the only thing they think they can do at this time--threaten the apostles. They desire to shut down the messengers! They want to minimize the influence of the gospel message, so they called them back in before the council and "commanded them not to speak at all nor teach in the name of Jesus" (Acts 4:18).
Would that stop Peter, John, and the other disciples? Absolutely not! Peter and John provide an answer that would have been perceived as defiant - "Whether it is right in the sight of God to listen to you more than to God, you judge. For we cannot but speak the things which we have seen and heard" (4:19,20). Their reply was simple and to the point. They were compelled to continue to teach that which they had witnessed, threats or not. Why? Because God had told them to do such, and they believed they should follow God's instructions over the Sanhedrin's. This reminds me of Paul in I Corinthians 9:16 - "For if I preach the gospel, I have nothing to boast of, for necessity is laid upon me; yes, woe is me if I do not preach the gospel!" Regardless of what the apostles did, someone would be displeased (either God or the Sanhedrin). They would wisely choose to obey God and risk the wrath of the council (cf. Matt. 10:28). May we always pursue heavenly wisdom that we may know that which is right in the sight of God and then have the courage of our convictions to follow through and do what is pleasing to the Lord!
After more threats were uttered, the apostles were released from custody (for now). The frustrated Sanhedrin was too afraid to punish them for they knew it would anger the people who were glorifying God for the miracle.