" According to has been called a prepositional phrase, but strictly speaking, according is a participle in the sense of agreeing, acceding, and to alone is the preposition." [1913 Webster]

"According to him, every person was to be bought." [1913 Webster]

"Our zeal should be according to knowledge." [1913 Webster]

"Is all things well,
According as I gave directions?" [1913 Webster]

"The land which the Lord will give you according as he hath promised." [1913 Webster]

According as, precisely as; the same as; corresponding to the way in which. According as is an adverbial phrase, of which the propriety has been doubted; but good usage sanctions it. See According, adv.

according, adv.

Accordingly; correspondingly. Shak. [1913 Webster]

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OXFORD DICTIONARY

according, adv.
1 (foll. by to) a as stated by or in (according to my sister; according to their statement). b in a manner corresponding to; in proportion to (he lives according to his principles).
2 (foll. by as + clause) in a manner or to a degree that varies as (he pays according as he is able).

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