Albert Barnes on Hebrews 13:19

That I may be restored to you the sooner. It is here clearly implied that the writer was deterred from visiting them by some adverse circumstances over which he had no control. This might be either by imprisonment, or sickness, or the want of a convenient opportunity of reaching them. The probability is, judging particularly from the statement in Heb 13:23, that he was then a prisoner, and that his detention was on that account. See Intro. & 4, (6.) The language here is such as Paul would use on the supposition that he was then a prisoner at Rome--and this is a slight circumstance going to show the probability that the epistle was composed by him.