Matthew 5:31

Ἐρρέθη δὲ ὅτι Ὃς ἂν ἀπολύσῃ τὴν γυναῖκα αὐτοῦ, δότω αὐτῇ ἀποστάσιον·

RBT Greek Interlinear:

Strongs 2046; Errethē; Ἐρρέθη; It was said; V-AIP-3S

Strongs 1161; de; δέ; however; Conj

Strongs 3739; Hos; Ὃς; Whoever; RelPro-NMS

Strongs 302; an; ἂν; conditional particle; Prtcl

Strongs 630; apolysē; ἀπολύσῃ; he might release; V-ASA-3S

Strongs 3588; tēn; τὴν; the; Art-AFS

Strongs 1135; gynaika; γυναῖκα; woman; N-AFS

Strongs 846; autou; αὐτοῦ; himself; PPro-GM3S

Strongs 1325; dotō; δότω; let him give; V-AMA-3S

Strongs 846; autē; αὐτῇ; herself; PPro-DF3S

Strongs 647; apostasion; ἀποστάσιον; a letter of divorce; N-ANS

RBT Translation:

βιβλίον ἀποστασίου - "Book of Cutting Down"

And it was said, "Whoever would release/set free the Woman of himself, let him give to herself a book of defection."

ספר כריתת "Book of Cutting Down"

For a man is taking a woman, and he has owned/ruled her, and he has become when she is not finding favor/grace within the eyes of himself because he has found within herself nakedness, he has arranged words and he has written to herself a book of cutting down, and he is giving it within the Hand of herself, and he is sending her away from the house of himself.
(Deuteronomy 24:1 RBT)

Thus He Is has spoken, "Where is this book of cutting down the mother of yourselves? Straightly I have sent herself away!"
(Isaiah 50:1 RBT)

LITV Translation:
It was also said, Whoever puts away his wife, "let him give her a bill of divorce." Deut. 24:1

ESV Translation:
“It was also said, ‘Whoever divorces his wife, let him give her a certificate of divorce.’