"Rethinking Judaism: Reconciling with the Past for the Sake of the Future"
Rabbi Sabath's Commentary in the Jerusalem Report on the last chapter of the Book of Genesis:
https://www.jpost.com/not-just-news/rethinking-judaism-reconciling-with-the-past-for-the-sake-of-the-future-385758
אביך צוה THY FATHER DID COMMAND — They altered the facts (they stated something that was false) for the sake of peace, for Jacob had given them no such command because Joseph was not suspect in his sight (Yevamot 65b)).
לאמר אביך צוה, he commanded that we should say what we have to say as something that originated with us and not with him, as he did not think for a moment that you might want to avenge yourselves on us. However, he consented that if we were worried, we could take the initiative and express our concerns to you.
According to Seforno there was a conversation between the brothers and Jacob but it was a conversation that the brothers started. Jacob did not think there was a need to give instructions to Joseph to forgive his brothers, but he gave the brothers permission to use his name.
אביך צוה לפני מותו. הוא תמוה שהרי יוסף לא זזה ידו מאביו בשעת מותו. ואיך צוה והוא לא ידע. ונראה שהשכילו להבינו אשר במה שאמר בברכת יוסף ויפזו זרועי ידיו ששבח אותו שלא ירה חצים וקשת להממררים לו בזה צוה להגיד כי כן מבוקשו:
This is surprising since Yosef did not leave his father's side at the time of his death. How could Yaakov have commanded something that Yosef did not know? And it seems that Yosef's brothers were clever in understanding that Yaakov's blessing to Yosef was praise that he did not respond in violence to those who rebelled against him and based on this his brother's intuited this request.
(א) ויבך יוסף בדברם אליו. תכף שהזכירו לו אביו בכה לגודל האהבה ונכמרו רחמיו, והנה אחיו בקשו ממנו מחילה, ולא באר הכתוב שמחל להם, וכבר בארו רז"ל שכל מי שחטא לחברו ועשה תשובה אינו נמחל לעולם עד שירצה את חברו, ואע"פ שהזכיר הכתוב וינחם אותם וידבר על לבם שנראה בזה שהיה להם רצוי מיוסף מכל מקום לא ראינו שיזכיר הכתוב מחילה ביוסף ולא שיודה להם שישא פשעם וחטאתם ואם כן מתו בענשם בלא מחילת יוסף ואי אפשר להתכפר עונם רק במחלתו ועל כן הוצרך העונש להיותו כמוס וחתום להפקד אחר זמן בענין עשרה הרוגי מלכות.
(1) ויבך יוסף בדברם אליו, “Joseph wept when they were speaking to him.” As soon as the brothers merely mentioned the name of their father Joseph already started weeping. This was due to the great love he had for his now departed father. This stirred his sense of compassion, especially seeing that his brothers asked his forgiveness. The Torah does not spell out that Joseph actually forgave his brothers. Our sages (Bava Kama 92) point out that if a person has wronged his fellow man and regrets this wrong and determines not to act in the manner which had offended his fellow man he is not forgiven by G’d until after he has made an effort to obtain forgiveness by the aggrieved party first. At any rate, the Torah is not on record anywhere that Joseph did forgive his brothers. This was the reason why the sin committed against Joseph resulted in the ten martyrs being executed by torture at the hands of the Romans.
וא"ר אילעא משום רבי אלעזר בר' שמעון: מותר לו לאדם לשנות בדבר השלום שנאמר (בראשית נ:טז-יז) "אביך צוה וגו כה תאמרו ליוסף אנא שא נא וגו."
ר' נתן אומר מצוה, שנאמר (שמואל א טז:ב) "ויאמר שמואל איך אלך ושמע שאול והרגני וגו."
R. Ilai in the name of R. Eleazar b. R. Shimon: One may modify a statement in the interest of peace, for it is said: "Your father commanded us before he died saying, So shall you say unto Joseph, Forgive, I pray you, the transgression of your brothers..."(Gen 50:16-17)
R. Nathan said: It is a commandment [to modify a statement in the interest of peace]. It is said, "Samuel said. How can I go? If Saul hear it he will kill me. And the Lord said, 'Take a heifer with you and say, I have come to sacrifice unto the Lord." (I Samuel 16:2)