Tafsiran Kejadian 17:20: Rashi, Chizkuni, Or HaChaim & Radak

שנים עשר נשיאים TWELVE PRINCES — like clouds shall they vanish, the word נשיאים being explained here as the same word in (Proverbs 25:14) נשיאים ורוח “Clouds and wind”

ולישמעאל שמעתיך, “and concerning Yishmael, I have heard your request, etc.” I am going to bless him, but I will not include him in My covenant with you which I will maintain with Yitzchok, the covenant that I concluded with you between the “pieces” as detailed in chapter 15. In the interpretation of the [covenant of] circumcision, the covenant is mentioned 13 times to teach you it symbolizes a man who is 13 years old and had not had circumcision in his youth, and he intentionally does not circumcises himself - he is liable for extirpation.

ולישמעאל שמעתיך, "Concerning (your prayer for) Ishmael, I have listened to you, etc." Inasmuch as the only reason Abraham had prayed for Ishmael was because he was at that time his only son, and he had not prayed for him again after Sarah had born Isaac, G'd listened to his prayer. We can understand this according to the principle postulated in Makkot 11 that even the conditional curse of a Torah scholar comes true. We have another principle that a blessing is much stronger than a curse, i.e. has far wider ramifications. G'd told Abraham that Ishmael would eventually become a בעל תשובה since Abraham had prayed for Ishmael to develop into a G'd-fearing person. This is the meaning of G'd's words: "Here I have blessed him." G'd used the past tense to hint that when He promised that Abraham would die in a ripe old age, He had already made provisions for Ishmael's conduct not to cloud Abraham's departure from this earth.