Ellicott's Commentary On The Whole Bible
Psalms 39 - Introduction
XXXIX.
“Undoubtedly,” says Ewald, “the finest elegy in the Psalter;” and the same scholar pronounces it original, so that the many points of similarity with the book of Job (see Notes, passim) must be taken to indicate the acquaintance of its author with this Psalm. Perhaps it is from this elegy that he takes up the problem offered by the contradictions of life which he carries so much farther. A short refrain (Psalms 39:5; Psalms 39:11) enriches the varied versification.
Title. — The inserted “even” assumes that Jeduthun was the choir-master or leader to whom the musical direction of the Psalm was assigned. But it is possible that the choir itself may have continued to be known by the name of the old master long after he had passed away. Jeduthun (variously written, as in the Hebrew here Jedithin) is identified with Ethan (1 Chronicles 15:17) the Merarite, who with Heman the Korahite and Asaph the Gershonite were appointed musical directors (1 Chronicles 15:19) of the Temple service. (Comp. titles of Psalms 62, 77)