I have been studying Luke’s genealogy a bit, unable yet to make much sense of it. (Admittedly, I came into the study with an agenda.) In comparison to Matthew’s genealogy and various others of the Old Testament, Luke’s is very different. I have noted some details of interest, given below. (J. A. Fitzmyer’s commentary on Luke [AB] was most helpful.)
None of the first twenty entries, from Jesus to Rhesa, find any OT support. Zerubbabel is the first in Luke's series (and the last in Matthew's) to share OT testimony (1Chron3.19). Luke's list has 78 entries, spanning 77 generations (Matthew's only having 42 names, stopping at Abraham; Luke's list from Jesus to Abraham is made up of 57 names). Luke makes the connection from David to Nathan, not Solomon (as in Matthew). Surely Luke has in mind David’s son, and not the prophet. Or does he? Is this shift significant? There are five mentions of "Matthat" or "Mattathias" in Luke (3.24, 25, 26, 31), one of which finds its way in Matthew (Mt1.14), and none of which are recorded in the OT. Luke mentions twice a "Levi" (3.24, 29), neither of which are in Matthew, and only the latter seeming to point to the patriarchal figure. And about that patriarchal figure, there are four patriarchal names in 3.29-30: Joseph, Judah, Simeon, and Levi. Luke mentions one "Eliezer", which has not OT referent, though Matthew names one "Eleazar" (Mt1.14).
Does any of this indicate that Luke has tampered with his genealogy? Fitzmyer says that, if we adopt the 25-30-year generational span, Luke's is more likely to be accurate in number over Matthew’s (Fitzmyer, 495). And, since Matthew has deliberately arranged his genealogy into three sets of fourteen generations (cf. Mt1.17), his seems most artificial. But, the sequence seems way out in Luke. What is Luke doing? The names I've noted above are those of former high priests, no doubt recognized by Theophilus (the high priest of 37-41AD). I. H. Marshall notes that in the times of the patriarchs, the names "Levi", etc., were only used in Israel after the exile, and thus Luke is designating names anachronistically (Marshall, Commentary on Luke [NIGTC], 160). Is Luke using a tradition, or improvising?
Additionally (and more to the point of my original agenda), I read in Marshall’s commentary that "H. Sahlin, 89, also suggests that the number of priestly names in the genealogy may indicate a desire to show that Jesus was a priestly Messiah" (Marshall, 161, citing Sahlin’s Der Messias und das Gottesvolk). Marshall himself does not believe that Luke is portraying Jesus as a priestly Messiah. And Sahlin’s comment does not necessitate such a conclusion. However, can Sahlin’s suggestion be validated? If so, what are the implications?