Book 1, Section 172 lists seven streams of water: Ganga, Yamuna, Saraswati, Vithashtha, Sarayu, Gomati and Gandaki. It also states that Ganga is known as Alakananda in the celestial sphere and Vaitarini in the ancestral sphere.
The story of Tapati suggests that the illuminator of the universe is Vivaswat who is also called Surya and Tapana. He has a son called Savitru and a daughter called Tapti. This is interesting because the sun is known by several names which includes Surya, Savitru, Vivaswat and Aditya. The root words savitru stands for "illuminating" and tapana (tap) stands for "heat" or "ardor" (also the root word for tapas).
One statement in the story of Vasishta: “When someone with power to prevent a crime being committed does not prevent it, he is also tainted by that crime”. Another statement in Section 197: “Morality is subtle. We do not know its course”.
There is an interesting discussion about whether a woman is allowed to have five husbands. In the original episode, Arjuna marries Draupadi during his lonely travel. When he comes home and wants to surprise his mother and calls for her, Kunti is busy and says “whatever it is, share with your brothers”! Kunti is surprised when she finds out what the surprise is, but it is too late. Kunti’s words have to be honored even though she said it without knowing the situation. It is interesting that everyone’s opinion was asked on how to resolve this dilemma, except that of Draupadi.
As the story goes, in a previous life, Draupadi had asked Lord Mahadeva to bless her with a husband like the Lord himself. She kept asking again and again, in fact, FIVE times. Therefore, her marriage to five husbands was preordained!
Vyasa’s explanation is that Lord Narayana came down to earth as Balarama and Krishna and Shri Devi was born as Draupadi from the sacrificial altar. She was preordained to marry five Indras’s of previous eons who were incarnate in the Pandavas. The word preordained is repeated in several places.
We learn that Yudhistra thught that it will be impossible to win a war with the Kauravas because of the presence of Bhishma, Drona, Kripa and Karna on their side due to loyalty. That is why he wanted Arjuna to go and get celestial weapons during the period of their vanavasa (stay in the forest). He uses this argument to calm down Bhima and Arjuna (also, moral on timing of actions and preparations).
In the section where Arjuna and Ulupi meet, Arjuna says among other things: “Virtue (dharma) is superior to the body and remains long after the body is gone”. Also, some statements which I interpret to mean: “Keeping a promise and a pledge is a virtue. We encounter several situations in life where our duties and morals come into conflict. Each one has an acceptable solution. Do not be rigid”. Dharma is not a rigid concept in the Vedic tradition unlike western ideas of ethics and morals. It will be difficult to write a law book based on the Vedas! Rigid codification seems to be a product of the western traditions and Greek logicians.