"It is later than you think" could not be expressed in Martian—nor could "Haste makes waste," though for a different reason: the first notion was inconceivable while the latter was an unexpressed Martian basic, as unnecessary as telling a fish to bathe. But "As it was in the Beginning, is now and ever shall be" was so Martian in mood that it could be translated more easily than "two plus two makes four"—which was not a truism on Mars.
Heinlein frames most of didactic and expository elements of the prose within conversations between characters, and tends to reserve the omniscient narrative voice for dry reportage of facts. But occasionally, as in this quote from Chapter VIII, the narration offers lessons in Martian and human culture alike. This quote is an early exploration of the differences between the mindsets of the two planets' cultures. Learning to bridge the gap between the two cultures will form the key challenge for Mike throughout the novel.
Rather than giving us a full, in-depth portrait of Martian thought processes, the narration instead illustrates Martian philosophy obliquely with examples of the difficulty of translation. The fact that our most basic mathematics do not translate suggests that the Martian understanding of math and sciences operate at a higher level than our own, which will be borne out by Mike's mental ability to make objects and people disappear. For example, two plus two need not be four if, like Mike, one seems to have access to more than the three physical dimensions we humans know. "As it was in the Beginning, is now and ever shall be" is a quote from the Bible, and the fact that it translates easily to Martian foreshadows Mike's attraction to Earthling religion as a bridge between his Martian learning and his human roots.