He who is hasty to love is hasty to hate.
A person who falls in love quickly may quickly come to hate, for he does not act moderately
(And because they were stubborn to accept the religion, it caused them to be stubborn to lose it. And the sages of Spain said, he who is hasty to love is hasty to hate – Shlomo Ibn Verga, "Shevet Yehuda", page 172.)
Translation
Expression (Hebrew)
הַמְמַהֵר בָּאַהֲבָה מְמַהֵר בַּשִּׂנְאָה
Definition (Hebrew)
אָדָם הַמְּמַהֵר לְהִתְאַהֵב עָלוּל גַּם לְמַהֵר וְלִשְׂנֹא כִּי אֵינוֹ פּוֹעֵל בִּמְתִינוּת.
("וּלְפִי שֶׁהָיוּ קְשִׁי עֹרֶף לְקַבֵּל דָּת, גָּרַם שֶׁהָיוּ קְשִׁי עֹרֶף לַאֲבֵדָה. וְאָמְרוּ חַכְמֵי סְפָרַד, הַמְּמַהֵר בְּאַהֲבָה מְמַהֵר בְּשִׂנְאָה" – שְׁלֹמֹה אִבְּן וִירְגָה/"שֵׁבֶט יְהוּדָה", פ ע"ב).