Riyad as-Salihin: The Book of Miscellany – Hadith No. 1590 — Umar bin Al-Khattab (May Allah be pleased with him) reported: I sought… (Hadith No. 1590)

'Umar bin Al-Khattab (May Allah be pleased with him) reported: I sought permission of the Prophet (ﷺ) to perform 'Umrah. He granted me leave and said, "Dear brother! Do not forget us in your supplications". ('Umar added): This is something I would not exchange for the whole world.Another narration is: He (ﷺ) said, "Include us, my dear brother, in your supplications." .

Explanation:

Reference: Riyad as-Salihin, The Book of Miscellany, Hadith No. 1590