Were gathered together translates a different form of the Greek verb “came together” in verse 34 and suggests a continuation of the scene begun in verse 34. Evidently the Pharisees have gathered about Jesus in the hopes that one of their experts in the Jewish Scriptures would be able to trap him with a question (verse 35), but now Jesus makes a counterattack with a question of his own. Die Bibel im heutigen Deutsch draws the connection between verses 34 and 41 in the following way: “34 When the Pharisees heard … they all came together … 41 Jesus turned to the Pharisees who had gathered….” New Jerusalem Bible and New English Bible show the relation between the two verses in similar fashion. Another good rendering is “Now while the Pharisees were still gathered there together.”

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .