There are two apparently contradictory statements about the laying of the foundations of the temple. One (Ezra v 16) says Sheshbazzar did it; the other (Zech iv 9) attributes it to Zerubbabel. I Esdras vi 20 states that Sheshbazzar laid the foundation of the house of Yahweh and that even though building operations had continued it had not yet been completed. Earlier in the same chapter (vi 2) it was noted that Zerubbabel and Jeshua began to build the temple in the second year of Darius. This tradition persisted down to the time of Sirach (Sirach xlix 11-12). Several observations are in order. There is no doubt that royal permission for the return of the Jews to reactivated their worship at Jerusalem was granted by Cyrus to Sheshbazzar. The legal document affirming that order was the one referred to in the Ezra passage; its authority was basic for the continuance of the work under Zerubbabel. The part played by Sheshbazzar is the problem. He could have initiated preparations for building the temple by gathering the requisite materials and clearing away the debris from the site (David had arranged the site and provided materials for the first temple). Or he might actually have laid the lower courses of the substructure (‘šyy’, “lower base or foundation”) upon which the first or foundational courses of the superstructure rested. Or his work was so insignificant it may have crumbled during the intervening years to that Zerubbabel had virtually to begin all over again. See further K. Galling, “Serubbabel und der Wiederaufbau des Tempels in Jerusalem,” in VuH, pp. 67-69. (Jacob M. Myers, Ezra Nehemiah [AB 14; New York: Doubleday, 1965], xxvii n. 20)
For another scholar addressing a genuine inconsistency in the biblical texts (this time, on King Josiah's reforms), see: