Ibn Ezra on Leviticus 20:16

לרבעה. שם הפעל ואם הוא בחיר״ק כמו בשברי לכם כי משקלי שמות הפועלים הם משתנים: AND LIE DOWN THERETO. Le-rivah (and lie down thereto) is an infinitive even though it is vocalized with a chirik,⁴⁷Le-rivah (and lie down thereto) is vocalized with a chirik rather than with a kamatz katan (le-rovah). Compare, le-korvah (Ex. 36:2). for the forms of the infinitive change. Compare, be-shivri (when I break) (Lev. 26:26).⁴⁸Be-shivri is vocalized with a chirik rather than with a kamatz katan (be-shovri).