The word "alas" is an expression of grief, pity, or concern. A similar word is "woe" which is an expression of great sorrow or distress.
Both words have similar meanings and may be used interchangeably depending on the context.
In today's gospel passage, Jesus began each sentence with "Alas" and in that passage the word appeared three times.
The reaction of the scribes and Pharisees to what Jesus was to launch a furious attack on Jesus and tried to force answers on Him on innumerable questions, setting trap to catch Him out in something He might say.
It was a violent reaction to those seemly harsh words of Jesus. But what are they reacting to?
Could it be like when we are at the dentist's chair and as he drills out the decay in our tooth, we twitch and jerk violently when the drill comes near to the nerve of the tooth?
Similarly the teachings of Jesus is meant to cleanse us and clear out all the decay from sin so that we can be healed and made whole again.
It will be painful but necessary. The teachings of Jesus may seem to hurt, but the Lord binds up the bruises of His people and heals the wounds He inflicted.