What is the meaning of "va'Yeilchu"? Where did they go?
Targum Yonasan: They went after their Yeitzer ha'Ra.
What does the Torah mean when it writes "Elohim asher Lo Yeda'um"?
Rashi: It means that they never saw in them any Divine power.
What does the Torah mean when it writes "ve'Lo Chalak lahem"?
Rashi #1: It means that Hashem did not give them (Yisrael) into their portion.
Rashi #2 (citing Targum Onkelos): It means that they did not do them any good - they did not give them anything. 1
Ramban: It means that Hashem did not place [angels] as ministers over Yisrael. 2
Hadar Zekenim #1: It means that Hashem did not make [the luminaries] to be served, but that they should serve the nations and illuminate for them!
Da'as Zekenim, Hadar Zekenim #2 and Rosh: It means that the gods are not Yisrael's portion - Hashem is. 3
Rashi: And "Lo Chalak lahem" means that they did not distribute to them any portion of inheritance.
Ramban: As He did regarding to the nations - Refer to Vayikra 18:25:1:1.
As the Pasuk writes in Eichah 3:24 "Chelki Hashem Amrah Nafshi", and in Tehilim 16:5 "Hashem M'nas Chelki".