לו ישמעאל יחיה
The ר'בחיי writes, (Breishis 21:14) "אברהם אבינו saw with his נבואה that his children the בני ישראל will suffer in the future from ישמעאל. No other nation will hate the בני ישראל as much as the ישמעאלים,
He therefore treated his son as an enemy and supplied him with bread & water, the way it says in משלי כ"ה
אם רעב שונאך האכילהו לחם ואם צמא השקהו מים"
Even though the Nazis killed six million Yidden, however as much as they hated Yidden the ישמעאלים hate us even more.
The Nazis weren't מוסר נפש to kill Yidden whereas the ישמעאלים commit suicide and allow their own people to get killed as long as they can ח"ו kill Yidden.
Perhaps this is what אברהם asked from Hashem "לו ישמעאל יחיה "
הלואי ישמעאל would care & yearn life for his own people and for himself.
An enemy who is a Kamikaze fighter is the most dangerous
hateful enemy one can have.