Vincent's NT Word Studies
41. Then (oun). Rev., rightly, therefore: because of His words.Murmured (eggoguzon). See on Jude 16, and compare 1 Corinthians x. 10; Philip. ii. 14. The word is constantly used in the Septuagint of the murmuring of Israel in the wilderness. Wyc., grudged of Him. So Chaucer, "Judas grucched agens the Maudeleyn whan sche anoynted the hed of oure Lord" ("Parson's Tale"); and Shakespeare,
"Served Without or grudge or grumbling." "Tempest" i., 2, 249.
At Him (peri autou). Implying that they addressed their remonstrances to Him. But peri means about or concerning. So Rev., properly, concerning.