Musnad Ahmad 30:368

Yazid narrated to us, Muhammad informed us, from Iyad ibn Dinar, from his father, that he heard Abu Hurairah saying: Abu al-Qasim (peace and blessings of Allah be upon him) said: "The first group of my nation to enter Paradise will be in the form of the moon on the night of the full moon. And those who follow them will be like the most brightly shining star in the sky."