John 2:17

His disciples remembered that it was written, Zeal for thy house shall eat me up.

This quotation is Psalms 69:9; and, again from Hendriksen:

The disciples witnessing this manifestation of the zeal of their Lord for the house of his Father, are filled with fear that Jesus may suffer what David had to endure in his day, namely, that his zeal in some way would result in his being consumed.[17]

And of course, as noted above, it was precisely this manifestation of the Saviour's zeal that set in motion against him the murderous animosity of the religious apparatus in Jerusalem, which never relented until a cross arose upon Golgotha.

Jesus never lost sight of the Messianic implications of the temple cleansings; and, in the second instance of it, he reminded the selfish concessionaires that the house of God's holy religion had never been intended as their private privilege and personal domain, but that "My house shall be called a house of prayer for all nations" (Mark 11:17; Isaiah 56:7), indicating that "all nations," including the Gentiles, were intended to be benefited through the coming Messiah. Thus, the sin of the money-changers was not merely against Israel, but against all mankind also. The strong Messianic implications of this bold deed were not altogether lost on the priests, for they immediately demanded a sign that would confirm Jesus' implied claim of Messiahship. The cleansing itself was an excellent sign, but that they rejected.