The tzaddik's true joy from yiras Hashem

בענין שמו של יצחק על שם הצחוק שמעתי מפי מו"ז ז"ל שכמו שנאמר על הרשע מצחק בע"ז וג"ע וש"ד.

Concerning Yitzchak's name, which is connected to "laughter" (tzechok), I heard from my grandfather z"l: just as it is said of the rasha that he "laughs/sports" with avodah zarah, arayos, and shefichas damim (idolatry, immorality, and bloodshed) —

His grandfather opens with the negative side of "laughter": for the wicked, the gravest sins are treated as light sport.

והיינו שעונות חמורים כשחוק בעיניו כמ"ש שחוק לכסיל ע' זמה.

That is, grave sins are like a joke in his eyes, as it says, "Like sport to a fool is committing lewdness."

The fool treats even severe aveiros as trivial amusement, taking nothing seriously.

כן להיפוך בהצדיק יצחק אבינו ע"ה הי' כל תחבולי היצה"ר כשחוק מה שלאדם אחר הר גבוה כי הי' איש קדוש מרחם עכ"ד.

So, conversely, by the tzaddik Yitzchak Avinu a"h, all the schemes of the yetzer hara were like a joke — what to another person is a high mountain — for he was a holy man from the womb; thus far his words.

For Yitzchak, the temptations that loom over others like a towering mountain were laughably small, since he was sanctified from birth. This concludes the grandfather's teaching.

ויתכן לומר כי אם שיצחק הי' לו מדת היראה והפחד יוכל להיות שלא הי' ניכר על פניו רק שמחה וחדוה כי באמת אין מי שישמח בעולם רק מי שהוא ירא ה' לאמיתו ואין לו שום פחד אחר.

And one may say: even though Yitzchak possessed the trait of yirah and fear (pachad), it could well be that what showed on his face was only simchah and joy — for in truth no one in the world truly rejoices except one who has genuine yiras Hashem and harbors no other fear.

Yitzchak's defining middah was awe of Hashem, yet far from being grim, this produced pure joy; only one who fears Hashem alone, and nothing else, is truly free to be happy.

מה גם אם הוא בן חורין מיצה"ר כיצחק שהי' מוכן לעולה לפני ה' רק שגזר ה' אל תשלח ידך אבל הי' מוכן לזה.

All the more so if he is free of the yetzer hara, like Yitzchak, who was ready to be offered as an olah before Hashem — only that Hashem decreed, "Do not stretch out your hand," yet he was fully prepared for it.

Yitzchak's readiness at the Akeidah to give his very life shows he was liberated from the yetzer hara, which makes his inner joy all the more complete.

והוא שמחה לצדיק יותר משמחת הרשע בהבלי עולם.

And this is a joy of the tzaddik greater than the joy of the rasha in the vanities of the world.

The tzaddik's joy, rooted in yiras Shomayim, far surpasses the hollow pleasure the wicked find in worldly nonsense.

ויתכן לומר שישמעאל רצה להדמות אליו בבחי' השמחה.

And one may say that Yishmael wished to resemble him in the aspect of joy.

Yishmael, too, was "metzachek" (sporting), trying to imitate Yitzchak's quality of joyfulness — but from the wrong, coarse side of laughter.

אבל שרה הנביאה ידעה להפריש שלשמחה זו מה עושה.

But Sarah the prophetess knew how to distinguish what this "joy" of his was doing.

With her nevuah, Sarah perceived that Yishmael's laughter was the corrupt kind, not the holy simchah of Yitzchak.

לכן אמרה לא יירש עם בני עם יצחק שידעו שיורש שלהם מוכן להיות מלא שמחה שע"ש זה קרא שמו יצחק:

Therefore she said, "He shall not inherit together with my son, with Yitzchak" — that they should know their heir is destined to be full of [true] joy, on account of which his name was called Yitzchak.

Sarah insisted Yishmael be sent away so that the true heir, Yitzchak — whose very name means the holy joy born of yiras Hashem — would carry forward that legacy of pure simchah.

Summary: The name Yitzchak ("laughter") has two opposite faces. For the rasha, laughter means treating grave sins as trivial sport; for the tzaddik Yitzchak, the schemes of the yetzer hara were laughably small. Precisely because Yitzchak's defining trait was yiras Hashem — and one who fears Hashem alone fears nothing else — his face shone with true simchah, the joy of one freed from the yetzer hara. Yishmael tried to imitate this joy from its coarse side, but Sarah discerned the difference and ensured the true heir of holy joy would be Yitzchak.