Charles H. Spurgeon on Psalms 141:5

Let the righteous smite me, etc. This verse is so obscure as to be almost unintelligible. According to the English versions, it expresses his willingness to be rebuked by good men for his benefit. But this sense is not only hard to be extracted from the words, but foreign from the context. Of the many contradictory interpretations which have been proposed the most probable is that which makes the sentence mean, that the sufferings endured by the good man, even at the hand of the wicked, are chastisements inflicted by a righteous God in justice and with mercy, and as such may be likened to a festive ointment, which the head of the sufferer should not refuse, as he will still have need of consolation and occasion to invoke God, in the midst of trials and of mischiefs yet to be experienced. —Joseph Addison Alexander.