"to extract," "to remove"
10th cent. The word probably originates in Iberian courts. In the earliest texts, the word meant "to obtain through legal channels," which corresponds to the ancient noun saca "judicial fine," "right of retraction" (see saca (1)). Because of its legal history, the best theory is the word derives from Gothic sakan "to dispute," which may have been a term for legal disputes during the Gothic period.
From Proto-Germanic *sakan- "to charge." From Proto-Indo-European *sh2g- "to confront," "to discern" (in religious and legal spheres).
Latin sagus "prophetic"
Old Irish saigid "to claim," Middle Welsh haeðu "to strive"
Gothic sakan "to reprimand," Old High German sahhan "to argue," Old Saxon sakan "to rebuke"
Ancient Greek ἡγέομαι (hegéomai) "to direct"
"On the basis of the original use of sacar as a legal term meaning 'to obtain judicially; to exempt,' Corominas had linked this verb to the documented Gothic legal term SAKAN 'to dispute, rebuke, reprimand', rejecting the long-accepted connection with the family of [Latin] SACCUS." ~ S. Dworkin, A History of the Spanish Language (2012) (citations omitted)