sandhi (yāva + ssu)
Analysis. yāva 'as far as, as long as' + ssu 'if', a conditional fusion: 'to whatever extent' or 'so long as'. The ssu particle is a shortened form of ce (if), making this a concessive or comparative construction expressing degree and condition.
Etymology. yāva is related to Sanskrit yāvat 'as far as, as long as', from a Proto-Indo-European root *yu̯ā- meaning 'to join, yoke'; cognate with Latin iugum 'yoke' and English yoke. The ssu/ce conditional particle represents Proto-Indo-European *kwe 'if'.
Meanings from the Digital Pāḷi Dictionary; morphology and etymology by Claude.
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