Our Gemara on Amud Aleph discusses famine conditions that could allow a person to leave Eretz Yisroel:

 

תנו רבנן: אין יוצאין מארץ לחוץ לארץ, אלא אם כן עמדו סאתים בסלע. אמר רבי שמעון: אימתי – בזמן שאינו מוצא ליקח, אבל בזמן שמוצא ליקח – אפילו עמדה סאה בסלע, לא יצא.

 

The Sages taught: One may not leave Eretz Yisrael to live outside of Eretz Yisrael unless the price of two se’a of grain stood at a sela, which is double its usual price. Rabbi Shimon said: When does this exception, permitting one to leave Eretz Yisrael under certain circumstances, apply? It applies when one is unable to find produce to buy, as he has no money. But when one has money and is able to find produce to buy, even if the price of a se’a of grain stood at a sela, he may not leave.

 

וכן היה רבי שמעון בן יוחאי אומר: אלימלך, מחלון וכליון, גדולי הדור היו, ופרנסי הדור היו; ומפני מה נענשו? מפני שיצאו מארץ לחוצה לארץ, שנאמר: ״ותהם כל העיר עליהן, ותאמרנה הזאת נעמי״. מאי ״הזאת נעמי״? אמר רבי יצחק, אמרו: חזיתם נעמי שיצאת מארץ לחוץ לארץ – מה עלתה לה?

 

And Rabbi Shimon ben Yoḥai would likewise say: Elimelech and his sons Mahlon and Chilion were prominent members of their generation and were leaders of their generation. And for what reason were they punished? They were punished because they left Eretz Yisrael to go outside of Eretz Yisrael, as it is stated concerning Naomi and Ruth: “And all the city was astir concerning them, and the women said: Is this Naomi?” (Ruth 1:19). 

 

The Gemara asks: What is the meaning of the phrase: “Is this Naomi”? How does this indicate that her husband and sons were punished for leaving Eretz Yisrael? Rabbi Yitzḥak says that the women said: Have you seen what befell Naomi, who left Eretz Yisrael for outside of Eretz Yisrael? Not only did she not escape tribulations there, but she lost her status entirely.

 

Our forefather, Avraham, also left Eretz Yisrael to escape a famine. As it states (Bereishis 12:10):

 

ויהי רעב בארץ וירד אברם מצרימה לגור שם כי־כבד הרעב בארץ

 

There was a famine in the land, and Abram went down to Egypt to sojourn there, because the famine was severe in the land.

 

Be’er Mayyim Chaim (ibid) uses our Gemara to explain the superfluous comment in the verse: “Because the famine was severe.” This explanatory clause emphasizes that the famine had to be severe before Avraham would leave Eretz Yisrael. 

 

In opposition to this, Ramban (ibid) famously holds Avraham to a higher standard, in that a person who has such routine providence should have only trusted in God:

 

ודע כי אברהם אבינו חטא חטא גדול בשגגה שהביא אשתו הצדקת במכשול עון מפני פחדו פן יהרגוהו, והיה לו לבטח בשם שיציל אתו ואת אשתו ואת כל אשר לו, כי יש באלהים כח לעזר ולהציל. גם יציאתו מן הארץ שנצטוה עליה בתחלה מפני הרעב עון אשר חטא, כי האלהים ברעב יפדנו ממות. ועל המעשה הזה נגזר על זרעו הגלות בארץ מצרים ביד פרעה, במקום המשפט שמה הרשע והחטא:

 

Know that Abraham our father unintentionally committed a great sin by bringing his righteous wife to a stumbling-block of sin on account of his fear for his life. He should have trusted that G-d would save him and his wife and all his belongings for G-d surely has the power to help and to save. His leaving the Land, concerning which he had been commanded from the beginning, on account of the famine, was also a sin he committed, for in famine G-d would redeem him from death. It was because of this deed that the exile in the land of Egypt at the hand of Pharaoh was decreed for his children. In the place of justice, there is wickedness and sin.

 

We do not usually find commentaries faulting revered Biblical figures beyond whatever is mentioned in Midrash or Gemara, with some notable exceptions. This is a genre of Jewish literature that requires its own separate study. That the Ramban took it upon himself to criticize the patriarch is so difficult to process that Rav Moshe Feinstein Z”TL (Darash Moshe ibid, also see vol II, p. 10, and Kol Ram by Rav A. Fishelis vol II, p. 22) says that this text must not be authentic and it is a mitzvah to erase from the Ramban. Yet, others echo the Ramban’s assertion, see Radak (ibid), and Rav Samson Rafael Hirsch (ibid 12:2) who even references the Ramban as an object lesson: The Torah wants us to see the struggles and errors of even the great people. 

 

Rav Ruderman ZT”L (Sichas Avodas Halevi, Mamar Bitachon V’hishtadlus, 13) also follows the Ramban, but contextualizes it as an error in judgment about his standing relative to God. Rav Ruderman quotes Chovos Halevavos (Gate of Bitachon, 3) who holds that persons of a particular high degree of piety, who are not enslaved to the physical lusts, may totally rely on God. They are not under the usual requirement that humans make reasonable efforts to assure their economic and personal welfare.

 

ואם הוא מגביר עבודת האלהים ובוחר ביראתו ובוטח בו בעניני תורתו ועולמו וסר מן הדברים המגנים וכוסף למדות הטובות לא יבעט במנוחה ולא יטה אל השלוה ולא ישיאהו היצר ולא יפת בכשפי העולם יסתלק מעליו טרח הגלגול והסבוב בהבאת טרפו מפני הסתלקות שני הפנים הנזכרים מעליו הבחינה והבעיטה בטובה ויבואהו טרפו בלי טרח ובלי יגיעה כפי ספוקו ומזונו כמו שנאמר (משלי י ג) לא ירעיב ה׳ נפש צדיק.

 

If a man strengthens himself in the service of G-d, resolves to fear Him, trusts in Him for his religious and secular matters, steers away from reprehensible things, strives for the good Middos (character traits), does not rebel in prosperity nor turn towards leisure, is not enticed by the evil inclination, nor seduced by the witchery of this world - the burden of exerting himself in the means to a livelihood will be removed from him, since the two reasons mentioned above no longer apply to him, namely, to test him on his choice and to protect him from rebelling during prosperity. His livelihood will come to him without strain.

 

Therefore, Rav Ruderman avers that Avraham made an error in self-assessment and judgment. Avraham humbly believed that he still was required to take physical steps to protect himself. The mistaken humility was the real sin. Rav Ruderman is making an object lesson that it can also be a sin to underestimate one’s ability and spiritual stature.

 

While Rav Ruderman’s thesis stands on its own merit in terms of its nuanced moral refinement and philosophy, in terms of peshat in Chovos Halevavos, I have a major difficulty. Chovos Halevavos may not be discussing how one should behave, but rather what post facto attitude one should take in relation to what occurs. He may just mean to say that for certain people, their sustenance will come without effort. That is different than maintaining an approach that one need not initially try to take steps at self-preservation. According to such an idea, Avraham appropriately took steps to save himself, all the while, still trusting in God.