The Internet Archive has PDF scans openly available for each of the first three volumes of Hermann Strack and Paul Billerbeck’s Kommentar zum Neuen Testament aus Talmud und Midrasch, 6 vols. (München: Beck, 1922–1961):1
In addition, there is also a combined PDF that includes vols. 1–3 and2
Each of the files is reasonably large (75.7–134 MB). So, they may take some time to load on slower connections or browsers.
Header image supplied by Internet Archive. ↩
Special thanks to Ronald van der Bergh for bringing this combined PDF to my attention in his comment below. ↩