A. The Midrash states that Balak was well aware that he could not curse Israel. He asked Bilam: 'What is your idea?' Bilam responded that he seeks to curse them as 'Yaakov.' But how could Balak believe that Rachav, who is a descendant of Yaakov, will succeed?
The greatest blessing for Yaakov, with all his spiritual heights, comes from HaShem. Therefore, Balak thought to set after him specifically through negative matters connected to Yaakov.
B. The explanations provided here are based on commentary from Tanchuma, which shows a difference between Yaakov and Yisrael: where Yaakov refers to the heel, representing humility and steadfastness in mitzvos.
The discussion then shifts to why Bilam uses 'Yaakov' rather than 'Yisrael' when seeking to harm them. Even though they usually employ 'Yisrael,' suggesting strength and uprightness, each has its unique function; actual distinction enhances their qualities individually.
C. From this matter's depth: Each stage in a Jew's service to HaShem can relate either to Yaakov or Yisrael with distinct activities reflective of these attributes as part of collective Kedusha.
Bilam's perception fails to understand this differentiation since he sees only physical existence and not the spiritual undercurrents binding them as people of faith fulfilling divine existence.
In conclusion, one's genuine essence bases itself on soul and adherence through Torah instruction; therefore maintaining observance aids solidifying holiness!