God welcomes all believers, without distinction of persons, under the new economy (Act 10:34, Act 10:35).
joined ... to ... Lord - (Num 18:4, Num 18:7). “Proselytes.”
separated - Proselytes from the Gentiles were not admitted to the same privileges as native Israelites. This barrier between Jews and Gentiles was to be broken down (Eph 2:14-16).
eunuch - (Act 8:27, etc.). Eunuchs were chamberlains over harems, or court ministers in general.
dry tree - barren (compare Luk 23:31); not admissible into the congregation of Israel (Deu 23:1-3). Under the Gospel the eunuch and stranger should be released from religious and civil disabilities.