Musar zu Tehillim 133:1

"Concerning this matter, Moshe worried and said, 'perhaps I have, G-d forbid, made a profane use of the anointing oil?' A heavenly voice came forth and called out, 'as the precious oil on the head descends on the beard of Aharon.., as the dew of Hermon' (Tehilim 133:2-3), just as the law of profane use of holy objects is not applicable to the dew of Hermon, so also there was no profane use of the anointing oil on the beard of Aharon. Aaron however, was still worried. He said, 'It may be that Moshe did not transgress, but perhaps I have transgressed'. Another heavenly voice came forth and said to him, 'Behold how good and how pleasant it is for brothers to dwell together' (Tehilim 133:1) - as Moshe is not guilty of profane use, so are you not guilty of profane use".

“How good and how pleasant it is, when brothers dwell together in unity” (Tehillim 133:1). This verse refers to the man who fears Hashem and involves himself in Torah study for pure motives and also in the pillar of Divine service, that is, prayer. For these two pillars go ahead of a man’s casket when he goes to the next world. Their voice precedes him like a herald, proclaiming, “Throughout this man’s life he walked with us in a single company, therefore even now we will not abandon him until we have brought him to his palace, which speaks entirely of his honor. Then they address the holy Torah, “How much honor and glory has this man earned on your account because he always adhered to the Torah of truth! Such is not the case, however, with one who pursues vanity and emptiness, studying Torah in a way that is blemished and false. This earns him only sorrow on top of sorrow.