וַיֹּ֣אמֶר בֹּ֔עַז בְּיוֹם־קְנוֹתְךָ֥ הַשָּׂדֶ֖ה מִיַּ֣ד נָעֳמִ֑י וּ֠מֵאֵת ר֣וּת הַמּוֹאֲבִיָּ֤ה אֵֽשֶׁת־הַמֵּת֙ קניתי [קָנִ֔יתָה] לְהָקִ֥ים שֵׁם־הַמֵּ֖ת עַל־נַחֲלָתֽוֹ׃
Then said Boaz: ‘What day thou buyest the field of the hand of Naomi—hast thou also bought of Ruth the Moabitess, the wife of the dead, to raise up the name of the dead upon his inheritance?’
Rashi on Ruth
And from Rus the Mo’avitess. You must buy [the inheritance], and she is not willing [to sell] unless you marry her.