What is the significance of the fact the Bil'am compared Yisrael to a lioness and to a lion?
Rashi #1: When they rise each morning from their sleep, they arouse themselves like a female lion and a lion 1 to grab Mitzvos, to don a Talis, to recite the Sh'ma and to put on Tefilin. 2
Malbim
What was Bil'am referring to when he said "Lo Yishkav ad Yochal Teref ... "?
Rashi #1: He was referring to the fact that Yisrael do not go to sleep at night before they devour and destroy the demons that prey on them - by reciting Keri'as Sh'ma al ha'Mitah, before they deposit their souls with Hashem. Consequently, if an army comes to attack them, Hashem protects them; He fights on their behalf and the enemy fall slain before Him. 1
Rashi #2 (citing Targum Onkelos) and Targum Yonasan: He meant that they will not settle in their land before killing the nations and inheriting their property (taking the spoil of the slain - Targum Yonasan). 2
Ramban: Beginning the conquest of Cana'an like a female lion and ending it like a lion. Refer to 23:24:1:1*/
What was Bil'am referring to when he concluded "ve'Dam Chalalim Yishteh"?
Rashi #1: He was prophesying that Moshe would not die before slaying the five kings of Midyan, 1 and that he (Bil'am) would die together with them. 2
Rashi #2 (citing Targum Onkelos): Refer to 23:24:2:2.
Why did Bil'am mention specifically "Dam Chalalim"?
Chulin, 36a: To teach us that the blood of Chalalim - that comes from a dead person is considered a beverage, but not Dam Kilu'ach - that flows from a wound whilst the animal or the person is sqtill alive - is not, and is therefore not Machshir food to become subject to Tum'ah. 1
Nidah, 19b: To teach us that blood the color of Chalalim is Machshir and Metame because of Kesem, 2 but not that is green or yellow (like an Esrog). 3
Nidah, 55b: To teach us that the blood that flows the wound of a Zav is Machshir - because 'What is the difference whether the the person is completely dead or half-dead'?