I agree that the inclusion of the pronominal εκαστος indicates urgency. The best I can tell, the reason why the verb is singular is because he is emphasizing that each person needs to be baptized. However, I’ve been attempting to find another place either in the GNT or LXX which uses a similar construction to shed light on this.

Yes, we are talking about different pronouns. My mistake, I misread your previous comments. I was speaking about the second υμων. As for the NIDNTTE, its on my list to purchase when I win the big one. Although, since I don’t play it is unlikely that I’ll get a hold of that set.

I suppose the only thing at stake here is a better understanding of what is meant by baptism in the name of Jesus. If it modifies both verbs (which I concede it is not likely), then there is a question as to what that expression means. I did some more studying on the “in the name of…” construction, and given its frequency in the LXX, I think I understand it now. Many commentators suggest this is an alternate baptismal invocation (cf. Matt. 28:19). I think it is rather a means unto communicating that baptism is an activity we engage in while acknowledging the Lordship, person, and work of Christ.