Teaching is best interpreted as the equivalent of an imperative (see comment at verse 19).

Some translations render them to include only those who have been baptized, and others make it refer to the people of all nations. Probably a reference to all people is more natural, since the command of Jesus does not say to baptize only some, and translators should not be specific in this verse in a way the text is not.

Observe is used of commandments in 19.17 and of instructions in 23.3; it is also the same verb translated “keep watch” in 27.36, 54, and the participle “guards” (28.4) is also derived from this same verb. Here translators can say “to do all the things I have commanded you” or “to live according to my commandments to you.”

Commanded is first used in 4.6 (translated “give … charge of”); it is found elsewhere in 15.4; 17.9; 19.7. Commentators note that the construction all that I have commanded is similar to one that is frequently employed in the Septuagint of God’s commands to Israel (for example, Exo 7.2; 23.22; 29.35; 31.11; Deut 1.41; 4.2; 6.6). Translators can have either “everything I have commanded you” or “all the commands I have given you” (so Barclay).

The expression and lo is not natural in contemporary English, so most translators drop it. But sometimes it is rendered as “And it will be” or “It will happen that.”

I am with you always also has its roots in the Old Testament (see Exo 3.12; Josh 1.5, 9; Isa 41.10; 43.5). It is often more natural to say “I will be with you always (or, at all times).”

The close of the age is the same expression used in 13.39. The period indicated here is that which extends from the time of Christ’s resurrection-exaltation to the end of the world. Translators can have “until the end of the world (or, the end of time).”

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .