Jamieson, Fausset and Brown on Acts 28:14-15

14-15. Where we found brethren--not "the brethren" (see on Ac 21:4), from which one would conclude they did not expect to find such [Webster and Wilkinson].

and were desired--"requested."

to tarry with them seven days--If this request came from Julius, it may have proceeded partly from a wish to receive instructions from Rome and make arrangements for his journey thither, partly from a wish to gratify Paul, as he seems studiously and increasingly to have done to the last. One can hardly doubt that he was influenced by both considerations. However this may be, the apostle had thus an opportunity of spending a Sabbath with the Christians of the place, all the more refreshing from his long privation in this respect, and as a seasoning for the unknown future that lay before him at the metropolis.

so we went toward Rome.