Albert Barnes Commentary Matthew 26:5

"But they said, Not during the feast, lest a tumult arise among people." — Matthew 26:5 (ASV)

Not on the feast day. Not during the feast. The feast lasted seven days. A vast multitude attended from all parts of Judea. Jerusalem is said to have contained at such times three million people.

Among such a multitude, there were frequent tumults and seditions; and the Sanhedrin was justly apprehensive that such an event would indeed happen if, openly and in the temple, they arrested a teacher as popular as Jesus and put him to death. They therefore sought how they might do it secretly and by guile.