They were glad - The joy that arises from the opportunity of murdering an innocent person must be completely infernal.

And when they heard it, they were glad,.... That such an opportunity offered, and from such a quarter, by one of his own disciples; so that it might be done more secretly and effectually, and with less blame to themselves:

and promised to give him money; any sum he should ask; and what was agreed upon were thirty pieces, or shekels of silver; and so the Ethiopic version here, instead of money, reads, "thirty pieces of silver"; See Gill on Matthew 26:15.

And he sought how he might conveniently betray him; after this promise, and upon this agreement: henceforward he sought the most fitting opportunity, and the best season of betraying his master into the hands of these men, when he was alone, and the multitude absent, and there was no danger of a tumult, or a rescue; See Gill on Matthew 26:16.

Money

See on Matthew 26:15.

He sought (ευζήτει)

Imperfect tense. He kept seeking: busied himself continuously from that time.

Conveniently (εὐκαίρως)

Might find a good opportunity (καιρός).

And when they heard it, they were glad, and promised to give him money. And he sought how he might conveniently betray him.

14:10,11 Judas Iscariot. See notes on Mt 26:14-16.

11. And when they heard it, they were glad, and promised to give him money-Matthew alone records the precise sum, because a remarkable and complicated prophecy, which he was afterwards to refer to, was fulfilled by it.

And he sought how he might conveniently betray him-or, as more fully given in Luke (Lu 22:6), "And he promised, and sought opportunity to betray Him unto them in the absence of the multitude." That he should avoid an "uproar" or "riot" among the people, which probably was made an essential condition by the Jewish authorities, was thus assented to by the traitor; into whom, says Luke (Lu 22:3), "Satan entered," to put him upon this hellish deed.

14:1-11 Did Christ pour out his soul unto death for us, and shall we think any thing too precious for him? Do we give him the precious ointment of our best affections? Let us love him with all the heart, though it is common for zeal and affection to be misunderstood and blamed; and remember that charity to the poor will not excuse any from particular acts of piety to the Lord Jesus. Christ commended this woman's pious attention to the notice of believers in all ages. Those who honour Christ he will honour. Covetousness was Judas' master lust, and that betrayed him to the sin of betraying his Master; the devil suited his temptation to that, and so conquered him. And see what wicked contrivances many have in their sinful pursuits; but what appears to forward their plans, will prove curses in the end.