What you premise is very uncertain; for—
1. There is no evidence that they met to hear the word. The object of the meeting was "to break bread;" and the preaching of Paul seems to have been incidental, and not by appointment.
2. It is not certain that "to break bread" means to partake of the Lord's Supper. The Greek word, translated, to break, is used very often in the New Testament in reference to ordinary meals. An instance occurs in Luke 24:35—"And they told what things were done in the way, and how he was known of them in breaking of bread."
But if what you assert were true, your inference is not necessary; for—
1. It is entirely proper, for aught we know to the contrary, to celebrate the Lord's Supper and hear preaching on any day of the week.
2. Perhaps this meeting was held at that particular time, because the Apostle and his company were "ready to depart on the morrow." It was probably a farewell meeting, as many learned men think, and the text itself seems to hint.
3. There is not one word said in the text about Sabbath-keeping; nor is there the least intimation, either in the text or context, that the disciples were accustomed to meet on the first day of the week for any purpose whatever.
But you say, Paul waited there seven days, and we have no account of his preaching till the last night of his stay, which was the first of the week. We reply, This is no evidence that he did not preach during the other six days. Luke tells us, in this same chapter, verses 2 and 3, that "he came into Greece, and there abode three months;" and he does not say that he preached once during that time. But a small part, indeed, of the doings of the Apostles is recorded.
It is a remarkable fact, that this text, which is the only one in the New Testament that speaks of public religious exercises on the first day of the week, is, at the same time, the only one in the Bible that directly proves, that this day is not the Sabbath. I have already proposed to give up the argument in favor of the seventh day, if you produce one apostolic example of unnecessary labor performed therein. Will you give up your argument for the first day on the same condition? I believe this verse furnishes such an example.
The text proves nothing for you, if Paul's sermon and the breaking of bread were not on the first day. The sermon was preached between evening and midnight, and the bread was broken between midnight and break of day, and then Paul set out on his journey. According to the Roman method of computing time, the breaking of bread, at least, was in the morning of the same day in which Paul traveled from Troas to Assos, and thence to Mitylene; and, according to the Jewish method, the sermon, the breaking of bread, and the journey from Troas to Mitylene, were all within the compass of the same "first day of the week." That Luke should follow the unnatural Roman method, is so unlikely as hardly to be supposable. Now, if Paul traveled unnecessarily from Troas to Mitylene, as it seems he did, on the first day of the week, surely that day was not then the Sabbath of the fourth commandment. This text, therefore, proves positively that the first day is not the Sabbath, on which account it is of no little value in this controversy.