First things First - Pirkei Avot

Seven traits characterize an uncultured (golem) person, and seven a sage. A sage:

(5) deals with first things first, and last things last;

Pirkei Avot, 5.7.(5)

Bartenura on Pirkei Avot 5:7:6

and he speaks to the first [point] first: And so did we find with the Holy One, blessed be He; since Moshe said to Him (Numbers 3:11), "'Who am I that I should go to Pharaoh'" - that is the first - "'and that I should bring out the Children of Israel'" - behold, the second. And the Holy One, blessed be He, answered about the first (Numbers 3:12), "'Since I will be with you'"; and about the second, "'in your bringing the people out from Egypt, you will serve God.'"

Rabbeinu Yonah on Pirkei Avot 5:7:7

and he speaks to the first [point] first and the last [point] last: And its explanation is not that he should answer about the first thing first, and about the last question last. Rather that if the first question is clarified by the last thing, he should elucidate that first, and then elucidate the first; so as to understand and clarify his answer and [so] that the thing will be assimilable for his listener. And that is why it is called first, [even if] it is last - because it precedes it [logically] and the first thing is clarified by it. And if the matter is the opposite, it is called last. And about this is it said, "to the first [point] first and the last [point] last." And this is from great wisdom and understanding of things. And the golem does not know from all of these [things].

Rambam on Pirkei Avot 5:7:1

And the third virtue is that he organizes his study and puts first what is fitting to put first and puts later what is fitting to put later. As this approach is very helpful in study. And that is his saying, "he speaks to the first [point] first and the last [point] last.