John Gill Commentary Luke 20:19

"And the scribes and the chief priests sought to lay hands on him in that very hour; and they feared the people: for they perceived that he spake this parable against them." — Luke 20:19 (ASV)

And the chief priests, and the Scribes, that same hour ,
&c.] As soon as he had delivered the above parable, together with that of the two sons:

sought to lay hands on him ;
they had a good will to it, being exceedingly gravelled with the question he put to them concerning John's baptism, which confounded them, and put them to silence; and with the parables he delivered, in which they were so manifestly pointed at:

and they feared the people ;
lest they should rise and stone them, as in (Luke 20:6) or rescue him out of their hands;

for they perceived that he had spoken this parable against them :
and that they were the husbandmen that had used the servants of God so ill, and would put to death the son of God, the Messiah; and who would at length be destroyed themselves, and the kingdom of God be taken from them, though they seem to detest and deprecate it, saying in (Luke 20:16) God forbid; that we should kill the heir, or that we should be destroyed, and the vineyard given to others: these things grievously nettled them, and exasperated them against him; but they knew not how to help themselves at present.