Comparative Particles - उपमार्थ निपात

Following is the explanation regarding particles in Nirukta - Chapter 1, Section 4: 

Particles (निपात) occur in various senses: in a comparative sense (उपमार्थ), in a conjunctive sense (कर्मोपसंग्रहार्थ), and as expletives (पदपूरणः).

Of them, the following four are used in the sense of comparison (उपमार्थ):

1. ‘इव’ (iva) - in classical Sanskrit (भाषा) as well as in Vedic Sanskrit (अन्वध्यायं) – “अग्निरिव” (Like Agni), "इंद्र इव" (Like Indra)

2. ‘न’ (na) has the sense of negation (प्रतिषेधार्थ) in classical Sanskrit, and both the sense of negation and comparison (उपमार्थ) in Vedic Sanskrit – “नेन्द्रं देवममंसत्” (They did not recognize Indra as a god)

The established use is to place it immediately before that which it makes negative and to place it immediately after that with which it compares – “दुर्मदासो न सुरायाम्” (Like hard drinkers of wine) – here it has the sense of comparison.

3.    ‘चिद्’ (cid) has many meanings:

a.    In the sentence - “आचार्यश्र्चिदिदं ब्रूयात्” (Will the teacher kindly explain it?) - it is used in the sense of respect (पूजायाम्)


From what root is the word ‘आचार्य’ (ācārya, teacher) derived?
i.    आचारं ग्राहयति – He makes one understand way to act (ācāra)
ii.    आचिनोत्यर्थान् – He holds (ācinoti) the knowledge
iii.    आचिनोति बुद्धिमिति – he develops (ācinoti) the mind (of the student)

b.    In the expression -  “दधिचित्”  (like curd) - it is used in the sense of comparison (उपमार्थ)

c.    In “कुल्माषांश्र्चिदाहर” (bring even the inferior grain)- it is used in the sense of contempt (अवकुत्सिते)

'कुल्मार्षाः' (kulmārṣāḥ, inferior grain) is so called because it is left behind by families - कुल्मार्षाः कुलेषु सीदन्ति

 

4.    ‘नु’ (nu) has many meanings:

a.    In the sentence- “इदं नु करिष्यति” (therefore he will do it) - it is used for assigning a reason (हेत्वपदेशे)

b.    In “कथं नु करिष्यति” (how pray will he do it?), “नन्वेतदकार्षीत्” (has he really done it?) - it is used for asking a question (अनुपृष्ट)

c.    In - “वृक्षस्य नु ते पुरुहूत् वयाः” (Of thee like the branches of a tree) - it is used in a sense of comparison (उपमार्थ)

'वयाः' (vayāḥ) means branch, it has the sense of movement from  ‘वी’ (vī) because a branch moves in the wind - वयाः शाखा वेतेः I वातायना भवन्ति
'शाखा' (śākhā, branches) are so called because they rest in the sky - शाखाः खशयाः