“Our forefather Avraham was tried with ten tests…”
The Avos D’R’ Nosson lists the events in Avraham Avinu’s life which are among the ten nisyonos. Yet, questions HaGaon HaRav Yaakov Kamenetzky, Avraham’s outstanding hachnosas orchim as he – a 100-year-old elderly man who had just undergone a bris milah -- sat at the doorway of his tent in the heat of a day, and then personally served the guests, is not counted among the ten nisyonos.
Moreover, not only wasn’t this factored as a nisayon, but when Avraham Avinu asked the orchim to take a little bit of water and wash their feet, and didn’t perform the mitzvah himself, the gemara in Bava Metzia 86 tells us that this eventually resulted in Moshe Rabbeinu striking the rock in the Midbar in order to bring forth water for Bnai Yisroel. Because of this wrongdoing, Moshe Rabbeinu could not enter Eretz Yisroel, and the entire course of history was changed.
Avraham Avinu represents the chesed of the Borei Olam in our world. His involvement in the mitzvah of hachnosas orchim never presented any challenge or difficulty for him personally. He perceived it very plainly as a basic requirement of his existence. Thus, any deficiency in this middah of chesed was judged as a severe oversight by Hashem.
Conversely, sending away Yishmoel and the akeidas Yitzchak, which contain elements of cruelty and contradict the middah of chesed, were extremely challenging for Avraham Avinu.
