John 20:26 - Matthew Poole's English Annotations on the Holy Bible

After eight days signifieth here the eighth day from the resurrection, counting the day wherein Christ rose for one; as we call those third day agues which have but one day's intermission, and those quartan agues which have but two days intermission; so it is said, Mark 8:31, after three days he shall rise again, that is, the third day. This appears the most probable sense of the phrase: the disciples beginning from Christ's resurrection to keep the first day of the week for the weekly sabbath, and having met on the resurrection day, met again that day seven night, hoping (probably) for such a presence of Christ with them in their meeting as they had before experienced; nor was their expectation vain. It appears also there, from Acts 20:7, and 1 Corinthians 16:2, that the Christians were wont ordinarily to meet together the first day of the week for religious exercises; which from Christ's resurrection, or institution, or both, is thought to be called the Lord's day, Revelation 1:10. Nor indeed do we read in all the Scripture of any congregation of Christians on the Jewish sabbath, but upon this day; though, indeed, we find that the apostles (and possibly some other Christians) did meet together with the Jews in their synagogues on their sabbath; but we have not so much as one instance after the resurrection of any congregation, where Christians only were assembled upon the Jewish sabbath. Thomas at this time was with them. It is said again that Christ came and stood in the midst of them, the doors being shut: concerning which phrase, See Poole on "1 Thessalonians 20:19".