योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-23, verse-13

अपरिज्ञातनीरागमार्ग मित्र शुभाकृते ।
मरुमार्गमहारण्यपान्थ स्वागतमस्तु ते ॥ १३ ॥

aparijñātanīrāgamārga mitra śubhākṛte ,
marumārgamahāraṇyapāntha svāgatamastu te 13

13. aparijñātanīrāgamārga mitra śubhākṛte
marumārghamahāraṇyapāntha svāgatam astu te

13. aparijñātanīrāgamārga,
śubhākṛte,
marumārghamahāraṇyapāntha mitra,
te svāgatam astu .

13. O friend, whose path to a water source is unknown, O one of auspicious form! O traveler of the great desert wilderness, welcome to you!

Words meanings summery:

• अपरिज्ञातनीरागमार्ग (aparijñātanīrāgamārga) - O whose path to a water source is unknown (whose path to a water source is unknown)

• मित्र (mitra) - O friend (friend)

• शुभाकृते (śubhākṛte) - O one of auspicious form (of auspicious form, of beautiful appearance)

• मरुमार्घमहारण्यपान्थ (marumārghamahāraṇyapāntha) - O traveler of the great desert wilderness (traveler of the great desert wilderness path)

• स्वागतम् (svāgatam) - welcome (welcome, well-come, fortunate arrival)

• अस्तु (astu) - may it be (let it be, may it be)

• ते (te) - to you (to you, for you)

Words meanings and morphology

अपरिज्ञातनीरागमार्ग (aparijñātanīrāgamārga) - O whose path to a water source is unknown (whose path to a water source is unknown)

(adjective)

Vocative, masculine, singular of aparijñātanīrāgamārga

aparijñātanīrāgamārga - whose path to a water source is unknown

Compound type : bahuvrīhi (aparijñāta+nīrāgamārga)

• aparijñāta – unknown, not fully understood
  adjective (masculine)
  past passive participle
  Negation 'a-' + pari- + √jñā (to know)
  Prefix: pari
  Root: jñā (class 9)
• nīrāgamārga – path of water's arrival/source
  noun (masculine)

मित्र (mitra) - O friend (friend)

(noun)

Vocative, masculine, singular of mitra

mitra - friend, companion, sun

शुभाकृते (śubhākṛte) - O one of auspicious form (of auspicious form, of beautiful appearance)

(adjective)

Vocative, masculine, singular of śubhākṛti

śubhākṛti - of auspicious or beautiful form/appearance

Compound type : tatpuruṣa (śubha+ākṛti)

• śubha – auspicious, good, beautiful, bright
  adjective (neuter)
• ākṛti – form, shape, appearance, figure
  noun (feminine)

Note: Used as an adjective addressing a masculine 'friend'.

मरुमार्घमहारण्यपान्थ (marumārghamahāraṇyapāntha) - O traveler of the great desert wilderness (traveler of the great desert wilderness path)

(noun)

Vocative, masculine, singular of marumārghamahāraṇyapāntha

marumārghamahāraṇyapāntha - traveler of a great desert wilderness

Compound type : tatpuruṣa (marumārga+mahāraṇya+pāntha)

• maru – desert, sandy waste
  noun (masculine)
• mārga – path, road, way
  noun (masculine)
• mahā – great, large, mighty
  adjective
• araṇya – forest, wilderness, desert
  noun (neuter)
• pāntha – traveler, wayfarer
  noun (masculine)
  Derived from path (path, road).

स्वागतम् (svāgatam) - welcome (welcome, well-come, fortunate arrival)

(noun)

Nominative, neuter, singular of svāgata

svāgata - well-come, welcome, good arrival

past passive participle (as adjective)

su- (well) + āgata (come, arrived)

Compound type : tatpuruṣa (su+āgata)

• su – good, well, excellent
  indeclinable
• āgata – come, arrived, returned
  adjective (neuter)
  past passive participle
  From √gam (to go) with prefix ā-.
  Prefix: ā
  Root: gam (class 1)

अस्तु (astu) - may it be (let it be, may it be)

(verb)

3rd person , singular, active, imperative (loṭ) of as

Root: as (class 2)

ते (te) - to you (to you, for you)

(pronoun)

Dative, singular of yuṣmad

yuṣmad - you (singular/plural)

Note: Can also be genitive, but dative fits 'welcome to you'.