ن ف سthe self, breath

النفس · al-nafs · the self

• Met in: V1 p3 ¶2: «وكتاب رياضة النفس», "the Book of Training the Self"; and ¶6: «وتزكية النفس عنه», "to purify the self of it".
• Dictionary form: نَفْس (corpus lemma, 295 times in the Quran). Plural أَنفُس, as in أَنفُسَهُمْ, "themselves" (2:9).
• Pattern: فَعْل (faʿl).
• Meaning here: The self, and especially the self with its appetites, which needs training and purifying. In other places نفس simply means "a person" or "oneself".

Ibn Faris, Maqāyīs al-Lugha, root نفس, vol 5, p 460

النون والفاء والسين أصل واحد يدل على خروج النسيم كيف كان، من ريح أو غيرها، وإليه يرجع فروعه

One origin: the going out of a breath (nasīm), whatever it is, of wind or anything else; all its branches go back to it. (So نَفَس is a breath; and the Quran says of the dawn إِذَا تَنَفَّسَ, "when it breathes", 81:18, Saheeh International.)

Urdu bridge

نفس is Urdu with the same meaning, usually the lower self (نفسِ امّارہ). نفسانی (of the self, carnal) and نفسیات (psychology) come from it. Arabic also uses نفس for "himself, themselves", which Urdu does not. (to be confirmed)

Quran

298 words from this root (Quranic Arabic Corpus). Most common: نَفْس ×295.

وَأَمَّا مَنْ خَافَ مَقَامَ رَبِّهِۦ وَنَهَى ٱلنَّفْسَ عَنِ ٱلْهَوَىٰ

But as for he who feared the position of his Lord and prevented the soul from [unlawful] inclination,

Surah An-Naazi'aat (79), ayah 40 · Saheeh International

Why this ayah: Holding the self back from its desires is the "training of the self" that the Ihya gives a book to.

In the Ihya

النفس: 852 times in the Ihya.