The most absurd customs and the most ridiculous ceremonies are everywhere excused by an appeal to the phrase, but that’s the tradition. This is exactly what the Hottentots say when Europeans ask them why they eat grasshoppers and devour their body lice. That’s the tradition, they explain.

[Les coutumes les plus absurdes, les étiquettes les plus ridicules, sont en France et ailleurs sous la protection de ce mot: c’est l’usage. C’est précisément ce même mot que répondent les Hottentots, quand les Européens leur demandent pourquoi ils mangent des sauterelles, pourquoi ils dévorent la vermine dont ils sont couverts. Ils disent aussi: c’est l’usage.]

Nicolas Chamfort
Nicolas Chamfort (1741-1794) French writer, epigrammist (b. Nicolas-Sébastien Roch)
Products of Perfected Civilization [Produits de la Civilisation Perfectionée], Part 1 “Maxims and Thoughts [Maximes et Pensées],” ch. 3, ¶ 249 (1795) [tr. Mathers (1926)]
    (Source)

(Source (French)). Alternate translations:

The most absurd conventions, the most ridiculous formalities enjoy in France and elsewhere the protection of the phrase, "It's the custom.” It is the very phrase with which the Hottentots answer when the Europeans ask them why they eat grasshoppers, why they devour the vermin that crawl on them. They too say, “It’s the custom.”
[tr. Merwin (1969)]

The most absurd habits, the most ridiculous matters of etiquette enjoy in France and elsewhere the protection afforded by this phrase: "It is the custom." It is precisely this phrase which Hottentots produce when Europeans ask them why they eat grasshoppers, and why they devour the vermin with which they are infested. They also say: "It is the custom."
[tr. Pearson (1973)]

The most absurd customs, the most ridiculous etiquettes, are in France and elsewhere under the protection of this phrase: That's how things are. That is precisely the phrase that Hottentots say when Europeans ask them why they eat locusts; why they consume the vermin that they are covered in. They saÿ: "That's how things are."
[tr. Siniscalchi (1994)]

In France and elsewhere, the most absurd customs and protocol are justified by the statement "It's always been done like that." That's exactly what Hottentots tell Europeans when asked why they feed on locusts or the vermin on their bodies: "It's what we've always done."
[tr. Parmée (2003), ¶161]