Then the experts in the law of Moses and the leading priests attempted to arrest Jesus right away, [but hesitated] because they feared [what] the people [might do], since they perceived that He had spoken this parable against them.

And the leading priests and experts in the law of Moses were looking for a way to kill Jesus because they were afraid of the people [i.e., that people would riot if it were done during the Festival. See Matt. 26:5].

So, from that day onward, the Jewish authorities began plotting [how] to kill Jesus.

Herodians

Then Jesus ordered them, saying, "Pay attention and watch out for the leavening [effect] of the Pharisees and Herod." [Note: By "Herod" is probably meant the Herodians, who were a party favorable to King Herod and, along with the Pharisees and Sadducees, were out to get Jesus. See Matt. 16:6].

Then the Pharisees sent certain ones of their number [See Matt. 22:15-16] along with the Herodians [Note: This refers to members of a political party favoring King Herod] to attempt to trap Him by what He said.

So, they sent their disciples, [along] with the Herodians to Him [Note: These were members of a political party favoring King Herod], saying, "Teacher, we know that you are sincere, and that you teach the truth about God's way. You do not care for [i.e., do not fear or give in to] anyone or allow the position of any person to influence you.

General references

Now it was the Sabbath day when Jesus had made the mud and restored the man's sight.