Majma al-Zawaid — Hadith 3327

Abd al-Rahman bin Humayd narrated from his father, from his grandfather, that the Prophet (peace and blessings be upon him) said: "The prayer of midday (al-hajir) is like the prayer of the night." The narrator said: I asked Abd al-Rahman bin Humayd about the word "hajir", and he said: "When the sun passes its zenith."
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators have been declared trustworthy.