Chasidut zu Bereschit 13:15

‎Genesis 13,16. “so that if one can count the dust of the earth then ‎your offspring too can be counted.” G’d’s comments were ‎triggered by Avram having seen in his astrology charts that he ‎was not going to have offspring. G’d taught him that “science” ‎such as astrology is valid only in terms of the terrestrial part of ‎the universe. Astrologers therefore are able to decipher only ‎matters accessible to ordinary people’s powers of perception. The ‎Jewish people’s fate could not be predicted on the basis of such ‎limited powers of perception. This is why Jews are not allowed to ‎attempt to count the stars as we know from Yuma 22, ‎where the Talmud states ‎כל המונה את ישראל עובר בלאו‎, “anyone ‎making a headcount of Israelites transgresses a negative ‎commandment.” The Talmud quotes Hoseah 2,1 in support of ‎this. The result of such a count would be misleading, as the ‎yardsticks that apply to other nations do not apply to the Jewish ‎people. Avram who had not yet been aware of this, had therefore ‎misread what appeared to be written in the stars concerning his ‎future. The Talmud Shabbat 156 cites our verse in support of this. ‎‎[The verses cited there are Genesis 15,4 and 5. Ed.] Basically, ‎seeing that our prayers and/or repentance have the power to ‎alter G’d’s decrees, how could constellations in the sky that are ‎predictable in advance have any bearing on our fate?‎