صَفًّا

A word in the Arabic language will either be 1) a verb or 2) a noun or 3) a particle – صَفًّا is a noun

A noun may either be 1) Definite or indefinite 2) Masculine or feminine 3) Singular, dual or plural 4) Nominative, accusative or genitive

صَفٌّ is the natural state of this indefinite noun and it changes to صَفًّا due to it being the: 1) المَفْعُوْلُ بِهِ object of a verb or 2) اسْمُ of إِنَّ or 3) خَبَرُ of كَانَ or 4) المَفْعُوْلُ فِيْهِ adverb of time or place or 5) المَفْعُوْلُ لَهُ noun that gives the reason for doing a thing or 6) المَفْعُوْلُ مَعَهُ noun that comes after the و which means “along with” or 7) المَفْعُوْلُ المُطْلَقُ is the مَصْدَرٌ of the verb occurring in the sentence or 8) الحَالُ adverb of manner or 9) التَّمْيِيْزُ noun that specifies the meaning of a vague word or 10) المُسْتَثْنَى noun that comes after إِلَّا meaning “except” or 11) المُنَادَى noun of calling or 12) it’s a noun of dependent declension a) نَعْتٌ / صِفَطٌ adjectives b) التَّوْكِيْدُ emphatic c) المَعْطُوْفٌ conjunction d) البَدَلُ synonym

Row; Rank

To set in order, array, arrange in a row or rank, extend and spread the wings in flying

نَكِرَةٌمُفْرَدٌمُذَكَّرٌمَنْصُوْبٌص ف فبَاب نَصَرَصَفَّ يَصُفُّفَعْلٌاسْمٌالصِّفَاتُ المُشَبَّهَةُ
IndefiniteSingularMasculineAccusativeRootTo classify / Line upنPatternNounA quality or descriptive noun
Surah/Below are the 6 verses in the holy Quran containing the nounصَفًّا
Verse 
and they will be presented before your Lord in rowsوَعُرِضُوا عَلَى رَبِّكَ صَفًّا
“certainly, you have come to Us as We created you the first timeلَّقَدْ جِئْتُمُوْنَا كَمَا خَلَقْنَاكُمْ أَوَّلَ مَرَّةٍ
18-48Nay you claimed that not We made for you an appointment”بَلْ زَعَمْتُم أَلَّن نَّجْعَلَ لَكُم مَّوْعِدًا
So gather your plan then come in ranksفَأَجْمِعُواْ كَيْدَكُمْ ثُمَّ ائْتُواْ صَفًّا
20-64and indeed he has succeeded today who overcomesوَقَدْ أَفْلَحَ الْيَوْمَ مَنِ اسْتَعْلَى
37-1By those arranged in ranks (rows)وَصَّافَّاتِ صَفًّا
61-4
the day the spirit and the angels will stand in rowsيَوْمَ يَقُوْمُ الرُّوْحُ وَالمَلَآئِكَةُ صَفًّا
they will not speak except whom the Most Merciful permits himلَّا يَتَكَلَّمُوْنَ إِلَّا مَنْ أَذِنَ لَهُ الرَّحْمَانُ
78-38and he will say what is correctوَقَالَ صَوَابًا
89-22and your Lord comes with the angels in rowsوَجَاءَ رَبُّكَ وَالمَلَكُ صَفًّا صَفًّا