Hath been set at liberty (απολελυμενον). Perfect passive participle of απολυω, to set free, in indirect discourse after γινωσκετε. Possibly from prison if he came to Rome at Paul's request (2. Timothy 4:11; 2. Timothy 4:21).

Shortly (ταχειον). Same comparative as in verse Hebrews 13:19, "sooner" than I expect (?).