made the graves of their prophets into places of worship, and so Allah Almighty cursed them. (1)
As for the second meaning, al-Munāwī says in Fayd al-Qadīr while commenting on the third ḥadīth cited above:
“Meaning, they turned those graves into the direction of their qiblah, under a false belief. Making them places of worship necessarily (2) entails building mosques upon them—and the converse is equally true. By this explanation he clarified the reason they were cursed: it lay in their excessive veneration. Al-Qāḍī (i.e., al-Bayḍāwī) said: When the Jews began to prostrate toward the graves of the prophets in reverence for their rank, making the graves a qiblah and facing them in prayer, they thereby turned them into idols. Allah therefore cursed them and forbade the Muslims from anything of that sort, warning them against it…”