WARNING:
WHEN ISAAC IS ALMOST THERE, ISHMAEL IS AROUND THE CORNER!
Meaning:
You who trust Hashem and wait for the promise, for the breakthrough, do not try to open the door yourself. Remember the story of Avraham and the birth of Ishmael, with the help of Sarah's plan to ask Hagar to conceive, with Avraham as the father. Ishmael was born of the flesh. Isaac, the miracle that G-d promised them so long ago and without human intervention.
Sarah could not get pregnant anymore because of her age, but for G-d NOTHING is impossible.
D'Vorah Meijer