Parshas Lech Lecha 5787
R’ Aryeh Leib Tzintz zt”l (Melo Haomer) writes as follows:
“'שכרך הרבה מאד' - Avraham did not daven for offspring earlier in his life because he understood that children are governed by mazal rather than standard merits (zechusim). Seeing in the stars that his astrological fate was to remain childless, he refrained from asking. Only after Hashem assured him of his extraordinary reward did Avraham recognize that his abundance of zechusim could break through the constraints of mazal - prompting him to finally ask for a child.”
A Wise Man would say: “It is easier to move mountains by faith than hills by your hands.”