Sayyiduna Anas bin Malik (may Allah be pleased with him) said: When Sayyidah Zaynab bint Rasulullah (peace and blessings be upon him) passed away, signs of grief appeared on the Prophet (peace and blessings be upon him), then it lifted from him. We said: O Messenger of Allah, we saw you grieved, then your grief lifted? He (peace and blessings be upon him) said: "I saw Zaynab and her weakness, and indeed it was made easy for her and for me; and she was squeezed with a squeeze that reached the east and the west."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19258