The Gemara in masechet Babba Bathra (14b) tells us who wrote the holy writings:

"And who wrote them? Moshe wrote his book (the Chumash) and Parshat Bilaam and Iyov (Job). Yehoshua wrote his book and eight verses in the Torah. Shmuel wrote his book and Shofetim and Ruth. David wrote the Book of Tehillim by means of ten sages (Rashi: incorporating their words)."

And the question arises: Parshat Bilaam is part of the Torah, so what does the Gemara mean by saying that Moshe wrote his book and Parshat Bilaam?

Rashi wrote: "And Parshat Bilaam – his prophecy and parables, even though they are not necessary for Moshe and his Torah and the (description of) the order of his deeds."
 

However, the Shla"h challenged the words of Rashi: "I did not merit to understand… are not all the stories in the Torah, like Cain's killing of Abel and others of that kind – they are apparently not necessary for the Torah and the order of Moshe's deeds, but it is all (part of) the 'Torah of HaShem is whole' and that which is written 'And Timna was the concubine' is HaShem's Torah like Shema Israel."
 

The Ritba wrote another, innovative explanation for Parshat Bilaam. He stated that the Gemara refers to a book of Bilaam's prophecies which they possessed. This is a novel explanation, as we have not found a book like this.

Another question relates to the judgement of Bilaam's character. Chazal said in Perek Helek (Sanhedrin 90a) that Bilaam was one of four commoners (as opposed to kings) who have no part in the World to Come. But in the verses he is portrayed as one who did nothing without asking permission from HaShem. "If Balak would give me his house filled with silver and gold, I will not be able to disobey the word of HaShem my Lord to do (anything) small or great."

And an even more difficult question: after he asks HaShem, and receives an answer that he can go with Balak's emissaries, why is the result "And HaShem's anger was provoked because he was going."?
 

In the words of the Abarbanel (Bamidbar 22): If the Blessed One permitted Bilaam to go, why is it written, after he went: "And HaShem's anger was provoked…" and he only went with His permission and His statement?

One explanation is that Bilaam was given permission to go with Balak's emissaries only in the physical sense (ללכת איתם) but not to share in their motives and ideals.  However, he went with them (עם שיר בלק) – in the sense of being equal with them - sharing their intentions.

A third question arises from the Mishna in Pirkei Avot:

"Everyone who has these three characteristics is of the students of Avraham Avinu, and (whoever has) three other (opposite) characteristics is of the disciples of the wicked Bilaam. A good (benevolent) eye, a humble spirit and a modest soul is of the students of Avraham Avinu. An evil (malicious) eye, an arrogant spirit and a greedy soul is of the disciples of the wicked Bilaam. What is (the difference) between the students of Avraham and the disciples of Bilaam?"

The question which arises is: why is the comparison made between the students of Avraham Avinu and the disciples of Bilaam, and not between Avraham and Bilaam themselves? Additionally, in order to ask what the difference is between them, we must assume that they were similar in some way, and we know that Avraham and Bilaam were complete opposites!

We can suggest a principle which answers all these questions. The Rambam states in Sefer HaMitzvot, Shoresh 1 that we are obliged to adhere to the words of the Sages, as we are commanded in the verse "do not stray" – meaning that this mitzvah includes the obligation to listen to the words of the Sages on every matter.
 

The Ramban found this surprising, and asked: if so, the punishment for transgressing a Rabbinical mitzvah should be flogging. Additionally: If Rabbinical commands are equivalent to commands from the Torah, why is it said that (in a situation of) a safek (doubt) regarding a Rabbinical command we should be lenient, while in the case of a safek in a Torah law we must be strict?

The Kovetz Shiurim, in Kuntres Divrei Sofrim, asks: if so, according to the Ramban, what obliges us to adhere to the words of Chachamim? And HaRav Elchanan Wasserman enlightens us the fact that the Sages reflect the will of the Torah, meaning: there are 613 mitzvot in the Torah, but in addition to the mitzvot there are things which are the will of the Torah – such is the way that HaShem wishes us to act, even though there is no explicit command for them, and the Sages who delve into the Torah are attuned to the will of the Torah.

 
"As (this) was also G-d's will, only He did not command us this with an explicit command, and therefore it can be said that this is the rule regarding all the mitzvot and prohibitions from their words (of the Sages) - that their objective corresponded to HaShem's objective. For example: when they prohibited sh'niot le'arayot (second-degree incest), such was HaShem's will that we should prohibit ourselves from sh'niot le'arayot, only He did not command this explicitly in the Torah. And for this reason, we are required to act according to their words, as by doing so we are doing the will of HaShem, since their will concurs with His will. Nevertheless, since these mitzvot are not commanded explicitly in the Torah, they are less severe than the word of the Torah. (Kuntres Divrei Sofrim Ch.1)"

Another example of this is the prohibition of Muktzeh, regarding which the Rambam writes: If one would be occupied with carrying his belongings from one place to another (on Shabbat) then the purpose which the Torah stated: "in order that (you) shall rest" will be nullified. In other words: the sages analyzed the intention of the Torah, and established their enactments and prohibitions according to the Torah's desire and intention.
 

In this spirit, we can answer all our questions regarding Bilaam. On one hand, he did only what HaShem told him, but he didn't follow HaShem's will or intention. Similarly, one can "formally" perform all the Mitzvot but not do HaShem's will which is behind the command. Obviously it wasn't HaShem's will that Bilaam should curse the nation which He chose and took out of Egypt. But Bilaam was duplicitous – he adhered to HaShem's command and ignored the Divine will, and therefore Chazal condemned him and HaShem was angry with him.

Perhaps this is the meaning of "Moshe wrote his book and Parshat Bilaam" - Parshat Bilaam indicates "the fifth volume of the Shulchan Aruch" – performing HaShem's commands as well as His will.

And therefore, as mentioned previously, there could appear to be a similarity between Avraham and Bilaam, because superficially Bilaam appeared to be righteous, and one could confuse between him and Avraham. Only in their students is the difference between them clearly seen.

In conclusion, the Ramban says regarding the verse "And you shall do what is upright and good" – that here the Torah expects us to strive toward the intention of the Torah, even with regard to what is not written explicitly in the Torah:
 

"And you shall do what is upright and good in HaShem's eyes" – the simple meaning is to observe HaShem's mitzvot, testimonies and statutes, and to perform them with the intention of doing only what is good and upright in HaShem's eyes. .. And our Rabbis associated a beautiful Midrash to this. They said: this is (exemplified by) compromise and going beyond the letter of the law (in order to peacefully resolve lawsuits). The meaning is: initially He said that you must observe His statutes and testimonies which He commanded you, and now He says to make sure to do the good and the upright in His eyes also in that which He did not command you, because He loves the good and the upright. And this is a great issue, since it is impossible to mention in the Torah all the interactions which people have with their neighbors and fellow men, and all the dealings and proper conduct in communities and countries, but after (the Torah) mentioned many of them, such as "do not go spreading gossip" "do not take revenge or hold a grudge" "do not stand (passively) by your fellow man's blood" "do not curse a deaf man" "stand up before the elderly" etc., the Torah went back to state as a general principle: do the good and the upright in all things, until this will come to include compromise and going beyond the letter of the law, and what they mentioned regarding the law of "bar matzra" (giving the owner of a field the first opportunity to purchase a field adjacent to his), and even what they said: one with an unstained reputation and his conversation with people is pleasant, to the point that he will be considered guileless and upright in every respect."
 

May we merit to fulfill the commandments of the Torah as well as to do the will of the Torah which is behind the commands.