وَلَا تُصَعِّرْ خَدَّكَ لِلنَّاسِ وَلَا تَمْشِ فِى ٱلْأَرْضِ مَرَحًا … وَٱقْصِدْ فِى مَشْيِكَ وَٱغْضُضْ مِن صَوْتِكَ إِنَّ أَنكَرَ ٱلْأَصْوَٰتِ لَصَوْتُ ٱلْحَمِيرِ
"Do not turn your cheek away from people, do not walk the earth in self-display… Be measured in your walk and lower your voice. The ugliest of voices is surely the voice of donkeys."
The concrete sense the lexicographers give is striking: ṣaʿar is a disease found in camels that leaves the neck bent to one side. From this comes the sense to turn the face away in pride, to turn one's cheek aside.
That is, the verse names a piece of conduct by the name of an animal disease. I record this as an observation: the proud bearing is described as a crookedness in need of correction — before any moral failing, a picture of a physical deformity is set up.
The root م-ر-ح was analysed at 40/75 in Ghāfir (al-Muʾmin) (joy that passes the measure, walking with a swagger). I do not repeat it.
ٱقْصِدْ — root ق-ص-د: to head for a goal; and to hold the middle way between excess and deficiency. The root was treated at 35/32 in Fāṭir (muqtaṣid — one who holds the middle way); I rely on that treatment.
The opposition of the two commands must be recorded: lā tamshi maraḥan (do not walk in self-display) / waqṣid fī mashyik (be measured in your walk). The same verb (to walk), twice over, once as a prohibition and once as a command.
And the particle is worth recording: ighḍuḍ min ṣawtik — "lower something of your voice". Min here is partitive (a part of it). That is, the verse asks not for silence but for the lowering of a part of the voice.
The question of the voice was treated in detail at 49/2-3 in al-Ḥujurāt (lā tarfaʿū aṣwātakum, yaghuḍḍūna aṣwātahum). I rely on that treatment, and I record the difference here: in al-Ḥujurāt the voice was lowered in the presence of the Prophet; in Luqmān the voice is tied to a measure for the whole of daily life.
أَنكَر — root ن-ك-ر: to go unrecognised, to be found strange. Ankar is an elative: "the most jarring, the ugliest". The root had already occurred in the seventeenth verse: wa'nha ʿani'l-munkar. The same root two verses apart, once for a deed and once for a sound. This is a repetition that can be verified from the text.
The harshness of the comparison is worth recording, and I give this as an observation: measured language has been used throughout the list; at the close an animal's voice is named outright. And the sound chosen is one that everyone in that setting heard every day. That is, the counsel is sealed not with an abstract description of good manners but with an example the ear recognises at once.